Isocyanate-functional silicone-polyether copolymer, silicone-polyether-urethane copolymer formed therewith, sealants comprising same, and related methods

ABSTRACT

An isocyanate-functional silicone-polyether copolymer having a particular structure is disclosed. A method of preparing the isocyanate-functional silicone-polyether copolymer is also disclosed, the method comprising reacting a polyether compound and an organosilicon compound to give the isocyanate-functional silicone-polyether copolymer. A silicone-polyether-urethane copolymer formed therewith, as well as a method of preparing the silicone-polyether-urethane copolymer, are also disclosed. Sealants comprising the isocyanate-functional silicone-polyether copolymer and/or the silicone-polyether-urethane copolymer are further disclosed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the National Stage of International Appl. No.PCT/US2018/039495 filed on 26 Jun. 2018, which claims priority to andall advantages of U.S. Provisional Application Nos. 62/524,637,62/524,636, and 62/524,639, filed on 26 Jun. 2017, the contents of whichare incorporated herein by reference.

FIELD OF THE INVENTION

The present invention generally relates to copolymers and, morespecifically, to an isocyanate-functional silicone-polyether copolymer,a silicone-polyether-urethane copolymer formed therewith, methods ofpreparing the same, and sealants comprising the same.

DESCRIPTION OF THE RELATED ART

Sealants are known in the art and are utilized in myriad end useapplications and environments. Physical and performance properties ofsealants, as well as the particular curing mechanism associatedtherewith, are generally selected based on the particular end useapplication and environment in which the sealants are utilized. Sealantscan be based on a variety of different chemistries and cure mechanisms.For example, sealants can be silicone-based and includeorganopolysiloxanes. Alternatively, sealants can be organic and includeorganic components, e.g. to form urethanes. Increasingly, hybridmaterials are utilized in sealants, which can combine the benefitstraditionally associated with silicone-based sealants and organicsealants.

For example, silane modified polyethers are increasingly utilized insealants as hybrid materials. However, existing silane modifiedpolyethers have limitations. For example, sealants includingconventional silane modified polyethers have undesirable cure speeds. Inaddition, such sealants may suffer from lesser heat stability than thosenot including hybrid materials and may undergo unintended side reactionsprior to or during curing.

BRIEF SUMMARY OF THE INVENTION

An isocyanate-functional silicone-polyether copolymer has the followingformula:

wherein each R¹ is an independently selected substituted orunsubstituted hydrocarbyl group having from 1 to 18 carbon atoms;subscript a is 0 or 1; D is a divalent hydrocarbon group having from 2to 18 carbon atoms; Y′ is a polyether moiety; and X is an isocyanatemoiety having at least one isocyanate functional group.

A method of preparing the isocyanate-functional silicone-polyethercopolymer is disclosed. The method comprises reacting asilicone-polyether copolymer and a polyisocyanate to give theisocyanate-functional silicone-polyether copolymer.

In addition, a method of preparing a silicone-polyether-urethanecopolymer is disclosed. The method comprises reacting theisocyanate-functional silicone-polyether copolymer with a coupling agenthaving an average of more than one isocyanate-reactive functional groupsto give the silicone-polyether-urethane copolymer.

Also disclosed is a silicone-polyether-urethane copolymer. Thesilicone-polyether-urethane copolymer has an average of more than onefunctional groups of the following formula:

wherein each R¹ is an independently selected substituted orunsubstituted hydrocarbyl group having from 1 to 18 carbon atoms;subscript a is 0 or 1; D is a divalent hydrocarbon group having from 2to 18 carbon atoms; and Y′ is a polyether moiety.

Sealants are also disclosed. In a first embodiment, the sealantcomprises a condensation reaction catalyst and further comprises theisocyanate-functional silicone-polyether copolymer. In a secondembodiment, the sealant comprises a condensation reaction catalyst andfurther comprises the silicone-polyether-urethane copolymer.

A cured product is additionally disclosed. The cured product is formedfrom the sealant. Further, a composite article and a method of preparingthe composite article are disclosed. The composite article comprises asubstrate and the cured product disposed on the substrate. The methodcomprising disposing the sealant on the substrate, and curing thesealant to give the cured product on the substrate, thereby preparingthe composite article.

DETAILED DESCRIPTION OF THE INVENTION

An isocyanate-functional silicone-polyether copolymer has the followingformula:

wherein each R¹ is an independently selected substituted orunsubstituted hydrocarbyl group having from 1 to 18 carbon atoms;subscript a is 0 or 1; D is a divalent hydrocarbon group having from 2to 18 carbon atoms; Y′ is a polyether moiety; and X is an isocyanatemoiety having at least one isocyanate functional group.

Each R¹ is independently selected and may be linear, branched, cyclic,or combinations thereof. Cyclic hydrocarbyl groups encompass aryl groupsas well as saturated or non-conjugated cyclic groups. Cyclic hydrocarbylgroups may be monocyclic or polycyclic. Linear and branched hydrocarbylgroups may independently be saturated or unsaturated. One example of acombination of a linear and cyclic hydrocarbyl group is an aralkylgroup. By “substituted,” it is meant that one or more hydrogen atoms maybe replaced with atoms other than hydrogen (e.g. a halogen atom, such aschlorine, fluorine, bromine, etc.), or a carbon atom within the chain ofR¹ may be replaced with an atom other than carbon, i.e., R¹ may includeone or more heteroatoms within the chain, such as oxygen, sulfur,nitrogen, etc. Suitable alkyl groups are exemplified by, but not limitedto, methyl, ethyl, propyl (e.g., isopropyl and/or n-propyl), butyl(e.g., isobutyl, n-butyl, tert-butyl, and/or sec-butyl), pentyl (e.g.,isopentyl, neopentyl, and/or tert-pentyl), hexyl, as well as branchedsaturated hydrocarbon groups of 6 carbon atoms. Suitable aryl groups areexemplified by, but not limited to, phenyl, tolyl, xylyl, naphthyl,benzyl, and dimethyl phenyl. Suitable alkenyl groups include vinyl,allyl, propenyl, isopropenyl, butenyl, isobutenyl, pentenyl, heptenyl,hexenyl, and cyclohexenyl groups. Suitable monovalent halogenatedhydrocarbon groups include, but are not limited to, a halogenated alkylgroup of 1 to 6 carbon atoms, or a halogenated aryl group of 6 to 10carbon atoms. Suitable halogenated alkyl groups are exemplified by, butnot limited to, the alkyl groups described above where one or morehydrogen atoms is replaced with a halogen atom, such as F or Cl. Forexample, fluoromethyl, 2-fluoropropyl, 3,3,3-trifluoropropyl,4,4,4-trifluorobutyl, 4,4,4,3,3-pentafluorobutyl,5,5,5,4,4,3,3-heptafluoropentyl, 6,6,6,5,5,4,4,3,3-nonafluorohexyl, and8,8,8,7,7-pentafluorooctyl, 2,2-difluorocyclopropyl,2,3-difluorocyclobutyl, 3,4-difluorocyclohexyl, and3,4-difluoro-5-methylcycloheptyl, chloromethyl, chloropropyl,2-dichlorocyclopropyl, and 2,3-dichlorocyclopentyl are examples ofsuitable halogenated alkyl groups. Suitable halogenated aryl groups areexemplified by, but not limited to, the aryl groups described abovewhere one or more hydrogen atoms is replaced with a halogen atom, suchas F or Cl. For example, chlorobenzyl and fluorobenzyl are suitablehalogenated aryl groups.

In certain embodiments, each R¹ is an independently selected alkylgroup. In specific embodiments, each R¹ is methyl.

Subscript a is 0 or 1. Typically, subscript a is 0.

Each D is an independently selected divalent hydrocarbon group havingfrom 2 to 18 carbon atoms, alternatively from 2 to 16 carbon atoms,alternatively from 2 to 14 carbon atoms, alternatively from 2 to 12carbon atoms, alternatively from 2 to 10 carbon atoms, alternativelyfrom 2 to 8 carbon atoms, alternatively from 2 to 6 carbon atoms,alternatively from 2 to 4 carbon atoms, alternatively 2 or 3 carbonatoms, alternatively 2 carbon atoms. Each D may independently be linearor branched. For example, when D has two carbon atoms, D has formulaC₂H₄, and may be linear (CH₂CH₂) or branched (CHCH₃). In certainembodiments, D is linear. When the silicone-polyether copolymer isprepared in bulk, in certain embodiments, at least 90 mol % of D arelinear.

Y′ is a polyether moiety. Y′ may be any polyether moiety including atleast one, alternatively at least two, ether moieties. Y′ is divalent.

In various embodiments, Y′ has the formula(C_(n)H_(2n)O)_(w)C_(m)H_(2m)—, wherein each subscript n isindependently selected from 2 to 4 in each moiety indicated by subscriptw; subscript w is from 1 to 200; and subscript m is from 2 to 4. Inthese embodiments, Y′ may comprise oxyethylene units (C₂H₄O),oxypropylene units (C₃H₆O), oxybutylene or oxytetramethylene units(C₄H₈O), or mixtures thereof, which may be in block form or randomizedin Y′.

For example, Y′ may have the formula—(C₂H₄O)_(x)(C₃H₆O)_(y)(C₄H₈O)_(z)C_(m)H_(2m)—, wherein subscript x isfrom 0 to 200; subscript y is from 1 to 200; subscript z is from 0 to200; subscript m is defined above; and wherein units indicated bysubscripts x, y and z may be in randomized or block form in Y′. Incertain embodiments, x and z are each 0 such that Y′ has the formula—(C₃H₆O)_(y)C_(m)H_(2m)—, where y and m are defined above. In specificembodiments, x and z are each 0, and m is 3, such that Y′ has theformula —(C₃H₆O)_(y)C₃H₆—.

The oxyalkylene units in Y′ may independently be linear or branched. Forexample, oxyethylene units, if present, may be of formula —CH₂CH₂O— orof formula —CHCH₃O—. Similarly, oxypropylene units may be of formula—CH₂CH₂CH₂O—, —CH₂CHCH₃O—, or —CHCH₃CH₂O—.

Y′ typically has a number average molecular weight (M_(n)) of at leastabout 100. In certain embodiments, Y′ has a M_(n) of at least 200,alternatively at least 300, alternatively at least 400, alternatively atleast 500, alternatively at least 600, alternatively at least 700,alternatively at least 1,000, alternatively at least 2,000,alternatively at least 3,000, alternatively at least 5,000,alternatively at least 10,000, alternatively at least 20,000,alternatively up to 30,000. In specific embodiments, Y′ has a M_(n) offrom 700 to 900. The number average molecular weight may be readilydetermined using Gel Permeation Chromatography (GPC) techniques based onpolystyrene standards or using end group analysis by nuclear magneticresonance spectroscopy.

X is an isocyanate moiety having at least one isocyanate functionalgroup. X is formed from a polyisocyanate when preparing theisocyanate-functional silicone-polyether copolymer, as described indetail below. When the polyisocyanate is a diisocyanate, X has oneisocyanate functional group. When the polyisocyanate is a triisocyanate,X has two isocyanate functional groups. As one specific example forillustrative purposes only, when the polyisocyanate utilized to preparethe isocyanate-functional silicone-polyether copolymer is 4,4′-methylenediphenyl diisocyanate, X has the following structure:

One of skill in the art readily understands the structure of X based onthe selection of the polyisocyanate. X is a residue of a polyisocyanatehaving one isocyanate functional group react to form theisocyanate-functional silicone-polyether copolymer and give X.

As described below, in certain embodiments, the polyisocyanate whichforms X is selected from the group of diphenylmethane diisocyanates(MDIs), polymeric diphenylmethane diisocyanates (pMDIs), toluenediisocyanates (TDIs), hexamethylene diisocyanates (HDIs), isophoronediisocyanates (IPDIs), naphthalene diisocyanates (NDIs), andcombinations thereof.

Exemplary polyisocyanates include, for example, m-phenylenediisocyanate, 2,4- and/or 2,6-toluene diisocyanate (TDI), the variousisomers of diphenylmethanediisocyanate (MDI),hexamethylene-1,6-diisocyanate, tetramethylene-1,4-diisocyanate,cyclohexane-1,4-diisocyanate, hexahydrotoluene diisocyanate,hydrogenated MDI (H12 MDI), naphthylene-1,5-diisocyanate,methoxyphenyl-2,4-diisocyanate, 4,4′-biphenylene diisocyanate, 3,3′-dimethyoxy-4,4′-biphenyl diisocyanate,3,3′-dimethyldiphenylmethane-4,4′-diisocyanate, 4,4′,4″-triphenylmethanediisocyanate, polymethylene polyphenylisocyanates, hydrogenatedpolymethylene polyphenyl polyisocyanates, toluene-2,4,6-triisocyanateand 4,4′-dimethyldiphenylmethane-2,2′,5,5′-tetraisocyanate. Thepolyisocyanate may be modified to include urea, isocyanurate,uretidinedione, allophonate, biuret, carbodiimide, urethane or otherlinkages.

A method of preparing the isocyanate-functional silicone-polyethercopolymer is disclosed. The method comprises reacting asilicone-polyether copolymer and a polyisocyanate to give theisocyanate-functional silicone-polyether copolymer.

The silicone-polyether copolymer may be any silicone-polyether copolymerwhich is capable of forming the isocyanate-functional silicone-polyethercopolymer. In certain embodiments, the silicone-polyether copolymer hasthe following formula:

wherein each R¹ is independently selected, and where R¹, subscript a,and D are as defined above; and where Y is a polyether moietyterminating with an OH group.

Y in the silicone-polyether copolymer becomes Y′ in theisocyanate-functional silicone-polyether copolymer. Thus, Y is selectedbased on the desired Y′. Y may be any polyether moiety including atleast one, alternatively at least two, ether moieties. Y is divalent,but becomes divalent as Y′ once reacted to give theisocyanate-functional silicone-polyether copolymer.

In various embodiments, Y has the formula—(C_(n′)H_(2n′)O)_(w′)C_(m′)H_(2m′)OH, wherein each subscript n′ isindependently selected from 2 to 4 in each moiety indicated by subscriptw′; subscript w is from 1 to 200; and subscript m′ is from 2 to 4. Inthese embodiments, Y may comprise oxyethylene units (C₂H₄O),oxypropylene units (C₃H₆O), oxybutylene or oxytetramethylene units(C₄H₈O), or mixtures thereof, which may be in block form or randomizedin Y.

For example, Y may have the formula—(C₂H₄O)_(x′)(C₃H₆O)_(y′)C₄H₈O)_(z′)C_(m′)H_(2m′)OH, wherein subscriptx′ is from 0 to 200; subscript y′ is from 1 to 200; subscript z′ is from0 to 200; subscript m′ is defined above; and wherein units indicated bysubscripts x′, y′ and z′ may be in randomized or block form in Y. Incertain embodiments, x′ and z′ are each 0 such that Y has the formula—(C₃H₆O)_(y′)C_(m′)H_(2m′)OH, where y′ and m′ are defined above. Inspecific embodiments, x′ and z′ are each 0, and m′ is 3, such that Y hasthe formula —(C₃H₆O)_(y′)C₃H₆OH.

The silicone-polyether copolymer may be prepared or obtained. Forexample, the silicone-polyether copolymer may be prepared by reacting apolyether compound having one terminal unsaturated group and oneterminal hydroxyl group and an organosilicon compound in the presence ofa hydrosilylation catalyst to give the silicone-polyether copolymer.

The polyether compound utilized in the method forms Y in thesilicone-polyether copolymer. Thus, the polyether compound utilized maybe selected based on the desired structure of the silicone-polyethercopolymer, e.g. based on molecular weight, the particular units withinY, etc.

In certain embodiments, the polyether compound has the average formulaR²O(C_(n′)H_(2′n)O)_(w′)C_(m′)H_(2m′)OH, wherein R² is an unsaturatedgroup having from 2 to 6 carbon atoms; each subscript n′ isindependently selected in each moiety indicated by subscript w′ and isdefined above; and subscript w′ is defined above. Those skilled in theart readily understand that impurities or alternative groups may existin the polyether compound which do not substantially diminish theutility or properties of the resulting silicone-polyether copolymerformed therewith. Examples of such impurities or alternative groupsinclude certain molecules of the polyether compound having two terminalunsaturated groups.

R² can be an alkenyl group or an alkynyl group. Specific examplesthereof include H₂C═CH—, H₂C═CHCH₂—, H₂C═CHCH₂CH₂—, H₂C═CH(CH₂)₃—,H₂C═CH(CH₂)₄—, H₂C═C(CH₃)—, H₂C═C(CH₃)CH₂—, H₂C═C(CH₃)CH₂CH₂—,H₂C═C(CH₃)CH₂CH(CH₃)—, H₂C═C(CH₃)CH(CH₃)CH₂—, H₂C═C(CH₃)C(CH₃)₂—, HC≡C—,HC≡CCH₂—, HC≡CCH(CH₃)—, HC≡CC(CH₃)₂—, and HC≡CC(CH₃)₂CH₂—.

In certain embodiments, the polyether compound has the formula—R²O(C₂H₄O)_(x′)(C₃H₆O)_(y′)C₄H₈O)_(z′)C_(m′)H_(2m′)OH, wherein R² isdefined above; subscript x′ is from 0 to 200; subscript y′ is from 1 to200; and subscript z′ is from 0 to 200; and wherein units indicated bysubscripts x′, y′ and z′ may be in randomized or block form in thepolyether compound. Generally, the polyoxyalkylene moieties indicated bysubscripts x′, y′, and z′ are nonreactive when forming thesilicone-polyether copolymer or the isocyanate-functionalsilicone-polyether copolymer. Each of the oxyalkylene units indicated bysubscripts x′, y′, and z′ may independently be branched or linear.

In specific embodiments, the polyether compound comprises onlyoxypropylene units (C₃H₆O). Representative, non-limiting examples ofsuch polyether compounds include: H₂C═CHCH₂O[C₃H₆O]_(y′)C₃H₆OH,H₂C═CHO[C₃H₆O]_(y′)C₃H₆OH, H₂C═C(CH₃)CH₂O[C₃H₆O]_(y′)C₃H₆OH,HC≡CCH₂O[C₃H₆O]_(y′)C₃H₆OH, and HC≡CC(CH₃)₂O[C₃H₆O]_(y′)C₃H₆OH, where y′is as defined above. Each oxypropylene unit may independently be offormula —CH₂CH₂CH₂O—, —CH₂CHCH₃O—, or —CHCH₃CH₂O—.

The polyether compound may be prepared by, for example, thepolymerization of ethylene oxide, propylene oxide, butylene oxide,1,2-epoxyhexane, 1,2-epoxyoctane, and/or cyclic epoxides, such ascyclohexene oxide or exo-2,3-epoxynorborane.

The polyether compound typically has a number average molecular weight(M_(n)) of at least about 100. In certain embodiments, the polyethercompound has a M_(n) of at least 200, alternatively at least 300,alternatively at least 400, alternatively at least 500, alternatively atleast 600, alternatively at least 700, alternatively at least 1,000,alternatively at least 2,000, alternatively at least 3,000,alternatively at least 5,000, alternatively at least 10,000,alternatively at least 20,000, alternatively up to 30,000. In specificembodiments, the polyether compound has a M_(n) of from 700 to 900. Thenumber average molecular weight may be readily determined using GelPermeation Chromatography (GPC) techniques based on polystyrenestandards or using end group analysis by nuclear magnetic resonancespectroscopy.

The organosilicon compound utilized in the method forms the siloxanemoiety of the silicone-polyether copolymer. The organosilicon compoundmay be any organosilicon compound suitable for forming thesilicone-polyether copolymer, as understood in the art. Typically, theorganosilicon compound is an organohydrogensiloxane compound includingat least one silicon-bonded hydrogen atom. The silicon-bonded hydrogenatom of the organohydrogensiloxane compound reacts with R² of thepolyether compound via a hydrosilylation reaction to give thesilicone-polyether copolymer.

In certain embodiments, the organosilicon compound is anorganohydrogensiloxane compound having the following formula:

wherein each R¹, subscript a, and D are as defined above.

Organohydrogensiloxane compounds can be made via any suitable technique.The organohydrogensiloxane compound may be prepared in accordance withthe methods disclosed in U.S. Provisional Pat. Appln. Nos. 62/524,637,62/524,636, and 62/524,639, the subject matter of which are incorporatedby reference herein.

The polyether compound and the organosilicon compound are typicallyreacted in a molar ratio of from 5:1 to 1:5; alternatively from 4:1 to1:4; alternatively from 3:1 to 1:3; alternatively from 2:1 to 1:2;alternatively to 1.1:1 to 1:1.1. The silicone-polyether copolymer istypically formed by a 1.2:1 molar ratio of the polyether compound andthe organosilicon compound, although a different molar excess of onerelative to the other may be utilized.

The silicone-polyether copolymer is formed by reacting the polyethercompound and the organosilicon compound in the presence of ahydrosilylation-reaction catalyst. The hydrosilylation-reaction catalystis not limited and may be any known hydrosilylation-reaction catalystfor catalyzing hydrosilylation reactions. Combinations of differenthydrosilylation-reaction catalysts may be utilized.

In certain embodiments, the hydrosilylation-reaction catalyst comprisesa Group VIII to Group XI transition metal. Group VIII to Group XItransition metals refer to the modern IUPAC nomenclature. Group VIIItransition metals are iron (Fe), ruthenium (Ru), osmium (Os), andhassium (Hs); Group IX transition metals are cobalt (Co), rhodium (Rh),and iridium (Ir); Group X transition metals are nickel (Ni), palladium(Pd), and platinum (Pt); and Group XI transition metals are copper (Cu),silver (Ag), and gold (Au). Combinations thereof, complexes thereof(e.g. organometallic complexes), and other forms of such metals may beutilized as the hydrosilylation-reaction catalyst.

Additional examples of catalysts suitable for thehydrosilylation-reaction catalyst include rhenium (Re), molybdenum (Mo),Group IV transition metals (i.e., titanium (Ti), zirconium (Zr), and/orhafnium (Hf)), lanthanides, actinides, and Group I and II metalcomplexes (e.g. those comprising calcium (Ca), potassium (K), strontium(Sr), etc.). Combinations thereof, complexes thereof (e.g.organometallic complexes), and other forms of such metals may beutilized as the hydrosilylation-reaction catalyst.

The hydrosilylation-reaction catalyst may be in any suitable form. Forexample, the hydrosilylation-reaction catalyst may be a solid, examplesof which include platinum-based catalysts, palladium-based catalysts,and similar noble metal-based catalysts, and also nickel-basedcatalysts. Specific examples thereof include nickel, palladium,platinum, rhodium, cobalt, and similar elements, and alsoplatinum-palladium, nickel-copper-chromium, nickel-copper-zinc,nickel-tungsten, nickel-molybdenum, and similar catalysts comprisingcombinations of a plurality of metals. Additional examples of solidcatalysts include Cu—Cr, Cu—Zn, Cu—Si, Cu—Fe—Al, Cu—Zn—Ti, and similarcopper-containing catalysts, and the like.

The hydrosilylation-reaction catalyst may be in or on a solid carrier.Examples of carriers include activated carbons, silicas, silicaaluminas, aluminas, zeolites and other inorganic powders/particles (e.g.sodium sulphate), and the like. The hydrosilylation-reaction catalystmay also be disposed in a vehicle, e.g. a solvent which solubilizes thehydrosilylation-reaction catalyst, alternatively a vehicle which merelycarries, but does not solubilize, the hydrosilylation-reaction catalyst.Such vehicles are known in the art.

In specific embodiments, the hydrosilylation-reaction catalyst comprisesplatinum. In these embodiments, the hydrosilylation-reaction catalyst isexemplified by, for example, platinum black, compounds such aschloroplatinic acid, chloroplatinic acid hexahydrate, a reaction productof chloroplatinic acid and a monohydric alcohol, platinumbis(ethylacetoacetate), platinum bis(acetylacetonate), platinumchloride, and complexes of such compounds with olefins ororganopolysiloxanes, as well as platinum compounds microencapsulated ina matrix or core-shell type compounds. Microencapsulated hydrosilylationcatalysts and methods of their preparation are also known in the art, asexemplified in U.S. Pat. Nos. 4,766,176 and 5,017,654, which areincorporated by reference herein in their entireties.

Complexes of platinum with organopolysiloxanes suitable for use as thehydrosilylation-reaction catalyst include1,3-diethenyl-1,1,3,3-tetramethyldisiloxane complexes with platinum.These complexes may be microencapsulated in a resin matrix.Alternatively, the hydrosilylation-reaction catalyst may comprise1,3-diethenyl-1,1,3,3-tetramethyldisiloxane complex with platinum. Thehydrosilylation-reaction catalyst may be prepared by a method comprisingreacting chloroplatinic acid with an aliphatically unsaturatedorganosilicon compound such as divinyltetramethyldisiloxane, oralkene-platinum-silyl complexes. Alkene-platinum-silyl complexes may beprepared, for example by mixing 0.015 mole (COD)PtCl₂ with 0.045 moleCOD and 0.0612 moles HMeSiCl₂, where COD represents cyclooctadiene.

Additional examples of suitable hydrosilylation catalysts for componentare described in, for example, U.S. Pat. Nos. 3,159,601; 3,220,972;3,296,291; 3,419,593; 3,516,946; 3,814,730; 3,989,668; 4,784,879;5,036,117; and 5,175,325; the disclosures of which are incorporatedherein by reference in their entireties.

The hydrosilylation catalyst may also, or alternatively, be aphotoactivatable hydrosilylation catalyst, which may initiate curing viairradiation and/or heat. The photoactivatable hydrosilylation catalystcan be any hydrosilylation catalyst capable of catalyzing thehydrosilylation reaction, particularly upon exposure to radiation havinga wavelength of from 150 to 800 nanometers (nm).

As introduced above, the silicone-polyether copolymer is reacted with apolyisocyanate to give the isocyanate-functional silicone-polyethercopolymer.

The polyisocyanate is not limited and may be an aliphatic,cycloaliphatic, araliphatic and/or aromatic polyisocyanate. Thepolyisocyanate advantageously contains at least 2.0 isocyanate groupsper molecule. A typical isocyanate functionality of the polyisocyanateis from about 2.0 to about 3.0 or from about 2.0 to about 2.5 isocyanategroups per molecule. However, the polyisocyanate may be utilized as ablend. When the polyisocyanate is utilized as a blend, thepolyisocyanate typically has a nominal functionality of at least 1.6,alternatively at least 1.7, alternatively at least 1.8.

In certain embodiments, the polyisocyanate is selected from the group ofdiphenylmethane diisocyanates (MDIs), polymeric diphenylmethanediisocyanates (pMDIs), toluene diisocyanates (TDIs), hexamethylenediisocyanates (HDIs), isophorone diisocyanates (IPDIs), naphthalenediisocyanates (NDIs), and combinations thereof.

Exemplary polyisocyanates include, for example, m-phenylenediisocyanate, 2,4- and/or 2,6-toluene diisocyanate (TDI), the variousisomers of diphenylmethanediisocyanate (MDI),hexamethylene-1,6-diisocyanate, tetramethylene-1,4-diisocyanate,cyclohexane-1,4-diisocyanate, hexahydrotoluene diisocyanate,hydrogenated MDI (H12 MDI), naphthylene-1,5-diisocyanate,methoxyphenyl-2,4-diisocyanate, 4,4′-biphenylene diisocyanate, 3,3′-dimethyoxy-4,4′-biphenyl diisocyanate,3,3′-dimethyldiphenylmethane-4,4′-diisocyanate, 4,4′,4″-triphenylmethanediisocyanate, polymethylene polyphenylisocyanates, hydrogenatedpolymethylene polyphenyl polyisocyanates, toluene-2,4,6-triisocyanateand 4,4′-dimethyldiphenylmethane-2,2′,5,5′-tetraisocyanate. Thepolyisocyanate may be modified to include urea, isocyanurate,uretidinedione, allophonate, biuret, carbodiimide, urethane or otherlinkages.

In certain embodiments, the polyisocyanate comprises a diisocyanate. Forexample, the diisocyante may have formula NCO-D′-OCN, wherein D′ is adivalent linking group. When the diisocyante comprises MDI, D′ is amethylene diphenyl moiety. However, the diisocyanate need not besymmetrical and the isocyanate functional groups need not be terminal.For example, the diisocyanate may have formula (NCO)₂-D′, where D′ isdefined above. The isocyanate functional groups may be bonded to thesame or different atoms within D′.

In certain embodiments, the polyisocyanate is an isocyanate-terminatedprepolymer. The isocyanate-terminated prepolymer is a reaction productof an isocyanate and a polyol and/or a polyamine, as understood in thepolyurethane art. The polyisocyanate may be any type of polyisocyanateknown to those skilled in the polyurethane art, such as one of thepolyisocyanates described above. If employed to make theisocyanate-terminated prepolymer, the polyol is typically selected fromthe group of ethylene glycol, diethylene glycol, propylene glycol,dipropylene glycol, butane diol, glycerol, trimethylolpropane,triethanolamine, pentaerythritol, sorbitol, and combinations thereof. Ifemployed to make the isocyanate-terminated prepolymer, the polyamine istypically selected from the group of ethylene diamine, toluene diamine,diaminodiphenylmethane and polymethylene polyphenylene polyamines,aminoalcohols, and combinations thereof. Examples of suitableaminoalcohols include ethanolamine, diethanolamine, triethanolamine, andcombinations thereof. It is to be appreciated that theisocyanate-terminated prepolymer may be formed from a combination of twoor more of the aforementioned polyols and/or polyamines.

The silicone-polyether copolymer and the polyisocyanate are typicallyreacted in a molar ratio of from 5:1 to 1:5; alternatively from 4:1 to1:4; alternatively from 3:1 to 1:3; alternatively from 2:1 to 1:2;alternatively to 1.1:1 to 1:1.1. The isocyanate-functionalsilicone-polyether copolymer is typically formed by a 1:1 molar ratio ofthe silicone-polyether copolymer and the polyisocyanate, although amolar excess of one relative to the other may be utilized.

In certain embodiments, the silicone-polyether copolymer and thepolyisocyanate are reacted to form the isocyanate-functionalsilicone-polyether copolymer in the presence of a catalyst. Examples ofcatalysts include tertiary amines; tin carboxylates; organotincompounds; tertiary phosphines; various metal chelates; metal salts ofstrong acids, such as ferric chloride, stannic chloride, stannouschloride, antimony trichloride, bismuth nitrate and bismuth chloride,and the like. Tertiary amine and tin catalysts are typical.

Exemplary examples of tertiary amine catalysts include trimethylamine,triethylamine, N-methylmorpholine, N-ethylmorpholine,N,N-dimethylbenzylamine, N,N-dimethylethanolamine,N,N,N′,N′-tetramethyl-1,4-butanediamine, N,N-dimethylpiperazine,1,4-diazobicyclo-2,2,2-octane, bis(dimethylaminoethyl)ether,bis(2-dimethylaminoethyl) ether, morpholine,4,4′-(oxydi-2,1-ethanediyl)bis, triethylenediamine, pentamethyldiethylene triamine, dimethyl cyclohexyl amine, N-cetyl N,N-dimethylamine, N-coco-morpholine, N,N-dimethyl aminomethyl N-methyl ethanolamine, N,N,N′-trimethyl-N′-hydroxyethyl bis(aminoethyl) ether,N,N-bis(3-dimethylaminopropyl)N-isopropanolamine, (N,N-dimethyl)amino-ethoxy ethanol, N,N,N′,N′-tetramethyl hexane diamine,1,8-diazabicyclo-5,4,0-undecene-7, N,N-dimorpholinodiethyl ether,N-methyl imidazole, dimethyl aminopropyl dipropanolamine,bis(dimethylaminopropyl)amino-2-propanol, tetramethylamino bis(propylamine), (dimethyl(aminoethoxyethyl))((dimethyl amine)ethyl)ether,tris(dimethylamino propyl) amine, dicyclohexyl methyl amine,bis(N,N-dimethyl-3-aminopropyl) amine, 1,2-ethylene piperidine andmethyl-hydroxyethyl piperazine.

Exemplary examples of tin-containing catalysts include stannous octoate,dibutyl tin diacetate, dibutyl tin dilaurate, dibutyl tin dimercaptide,dialkyl tin dialkylmercapto acids, dibutyl tin oxide, dimethyl tindimercaptide, dimethyl tin diisooctylmercaptoacetate,dimethyltindineodecanoate, and the like.

A method of preparing a silicone-polyether-urethane copolymer is alsodisclosed. The method comprises reacting an isocyanate-functionalsilicone-polyether copolymer with a coupling agent having an average ofmore than one isocyanate-reactive functional groups to give thesilicone-polyether-urethane copolymer.

The coupling agent may be any suitable coupling agent having an averageof more than one isocyanate-reactive functional groups. The couplingagent may be selected, for example, from any coupling agent or chainextender utilized in the urethane art.

The isocyanate-reactive groups of the coupling agent are independentlyselected and may be, for example, hydroxyl, primary amino or secondaryamino groups. Hydroxyl groups are most typical. Examples ofhydroxyl-containing coupling agents are ethylene glycol, 1,2-propanediol, 1,3-propane diol, 1,4-butane diol,2,2,4-trimethylpentane-1,3-diol, 2-ethylhexane diol,N,N-bis(2-hydroxylpropyl)aniline, diethylene glycol, triethylene glycol,dipropylene glycol, tripropylene glycol, cyclomethanedimethanol, and thelike. Among these, the linear, acyclic, hydroxyl-functional couplingagents are typical, and α,ω-alkylene glycols and α,ω-polyalkyleneglycols such as ethylene glycol, 1,4-butane diol, 1,3-propane diol,diethylene glycol, triethylene glycol and the like are most typical.

The examples of hydroxyl-containing coupling agents above are generallydiols. However, the coupling agent may have more than twoisocyanate-reactive groups. In certain embodiments, the coupling agentcomprises at least one on a triol, a tetraol, a pentaol, and a hexaol.In such embodiments, the hydroxyl-containing coupling agent may bereferred to as a polyhydroxyl compound. Specific examples ofpolyhydroxyl compounds include glycerol, erythritol, sorbitol, etc.

In certain embodiments, the isocyanate-functional silicone-polyethercopolymer and the coupling agent are reacted in the presence of acatalyst to give the silicone-polyether-urethane copolymer. The catalystmay be any suitable catalyst, for example the catalyst may be selectedfrom tertiary amines; tin carboxylates; organotin compounds; tertiaryphosphines; various metal chelates; metal salts of strong acids, such asferric chloride, stannic chloride, stannous chloride, antimonytrichloride, bismuth nitrate and bismuth chloride, and the like.Specific examples thereof are set forth above.

The silicone-polyether-urethane copolymer has an average of more thanone functional groups of the following formula:

wherein R¹, subscript a, D, and Y′ are defined above.

Generally, the number of functional groups in thesilicone-polyether-urethane copolymer represented above is contingent onthe number of isocyanate-reactive functional groups in the couplingagent. When the coupling agent includes two isocyanate-reactivefunctional groups, the silicone-polyether-urethane copolymer has twosuch functional groups. When the coupling agent includes threeisocyanate-reactive functional groups, the silicone-polyether-urethanecopolymer has three such functional groups.

In certain embodiments, the coupling agent has the formula X′-D″-X′,where X′ is an independent selected isocyanate-reactive group and D″ isa divalent linking group. By way of example, when the coupling agent isethylene glycol, each X′ is OH and D″ is CH₂CH₂. One of skill in the artreadily understands D″ and X′ based on the exemplified coupling agentsset forth above which have formula X′-D″-X′.

In these embodiments, the silicone-polyether-urethane copolymer has theformula Q-D″-Q, wherein D″ is the divalent linking group defined above,and each Q has the following formula:

wherein R¹, subscript a, D, and Y′ are defined above.

A sealant comprising the isocyanate-functional silicone-polyethercopolymer and/or the silicone-polyether-urethane copolymer is alsoprovided. More specifically, the sealant comprises: (I) a copolymercomprising at least one of the isocyanate-functional silicone-polyethercopolymer and the silicone-polyether-urethane copolymer; and (II) acondensation reaction catalyst. For purposes of clarity and consistency,reference herein to the (I) copolymer refers to theisocyanate-functional silicone-polyether copolymer, thesilicone-polyether-urethane copolymer, as well as combinations thereof,depending on the particular sealant.

The (I) copolymer comprises at least one of the isocyanate-functionalsilicone-polyether copolymer and the silicone-polyether-urethanecopolymer described herein. In certain embodiments, the (I) copolymercomprises, alternatively is, the isocyanate-functionalsilicone-polyether copolymer. In particular embodiments, the (I)copolymer comprises, alternatively is, the silicone-polyether-urethanecopolymer. In various embodiments, the (I) copolymer comprises each ofthe isocyanate-functional silicone-polyether copolymer and thesilicone-polyether-urethane copolymer described herein.

The (II) condensation reaction catalyst is not limited and, in someembodiments, is exemplified by tin catalysts, titanium catalysts,zirconate catalysts, and zirconium catalysts. General examples ofsuitable tin catalysts include organotin compounds where the valence ofthe tin is either +4 or +2 (e.g. tin (IV) compounds and/or tin (II)compounds). Specific examples of tin (IV) compounds include stannicsalts of carboxylic acids such as dibutyl tin dilaurate, dimethyl tindilaurate, di-(n-butyl)tin bis-ketonate, dibutyl tin diacetate, dibutyltin maleate, dibutyl tin diacetylacetonate, dibutyl tin dimethoxide,carbomethoxyphenyl tin tris-uberate, dibutyl tin dioctanoate, dibutyltin diformate, isobutyl tin triceroate, dimethyl tin dibutyrate,dimethyl tin di-neodeconoate, dibutyl tin di-neodeconoate, triethyl tintartrate, dibutyl tin dibenzoate, butyltintri-2-ethylhexanoate, dioctyltin diacetate, tin octylate, tin oleate, tin butyrate, tin naphthenate,dimethyl tin dichloride, a combination thereof, and/or a partialhydrolysis product thereof. Additional examples of tin (IV) compoundsare known in the art and are commercially available, such as Metatin®740 and Fascat® 4202 from Acima Specialty Chemicals of Switzerland,Europe, which is a business unit of The Dow Chemical Company, as well asFormrez® UL-28 from Galata Chemicals of Hahnville, La. Specific examplesof tin (II) compounds include tin (II) salts of organic carboxylic acidssuch as tin (II) diacetate, tin (II) dioctanoate, tin (II)diethylhexanoate, tin (II) dilaurate, stannous salts of carboxylic acidssuch as stannous octoate, stannous oleate, stannous acetate, stannouslaurate, stannous stearate, stannous naphthanate, stannous hexanoate,stannous succinate, stannous caprylate, and a combination thereof.Examples of suitable titanium catalysts include titanium esters such astetra-n-butyltitanate tetraisopropyltitanate,tetra-2-ethylhexyltitanate, tetraphenyltitanate, triethanolaminetitanate, organosiloxytitanium compounds, and dicarbonyl titaniumcompounds, such as titanium ethyl acetoacetate,diisopropoxydi(ethoxyacetoacetyl) titanium andbis(acetoacetonyl)-diisopropoxy titanium (IV). Many of these titaniumcatalysts are commercially available, such as Tyzor™ DC, Tyzor™ TnBT,and Tyzor™ 9000 from Doft Ketal Specialty Catalysts LLC of Houston, Tex.In certain embodiments, the (II) condensation reaction catalyst is atitanium catalyst, such as one of those exemplified above, e.g. wherethe sealant is or may be formulated as a room temperature vulcanizingsealant composition. The amount of the (II) condensation reactioncatalyst present in the sealant depends on various factors (e.g. theamount and/or type of the (I) copolymer, the types and/or amounts of anyadditional materials present in the sealant, etc.), and may be readilydetermined by one of skill in the art. Typically, the sealant comprisesthe (II) condensation reaction catalyst in an amount of from 0.2 to 6,alternatively from 0.5 to 3, parts by weight based on the total weightof the (I) copolymer present in the sealant.

In some embodiments, the sealant further comprises one or moreadditives. Examples of suitable additives that may be present in thesealant include fillers, treating agents (e.g. filler treating agents),cross-linkers, adhesion promotors, surface modifiers, drying agents,extenders, biocides, flame retardants, plasticizers, end-blockers,binders, anti-aging additives, water release agents, pigments, rheologymodifiers, carriers, tackifying agents, corrosion inhibitors, catalystinhibitors, viscosity modifiers, UV absorbers, antioxidants,light-stabilizers, and the like, as well as combinations thereof.

In certain embodiments, the sealant includes a filler. The filler may beor comprise a reinforcing filler, an extending filler, a conductivefiller (e.g., electrically conductive, thermally conductive, or both),or the like, or a combination thereof. Examples of suitable reinforcingfillers include precipitated calcium carbonates and reinforcing silicafillers such as fume silica, silica aerogel, silica xerogel, andprecipitated silica. Specific suitable precipitated calcium carbonatesinclude Winnofil® SPM from Solvay and Ultrapflex® and Ultrapflex® 100from Specialty Minerals, Inc. Examples of fumed silicas are known in theart and are commercially available, such as those sold under the nameCAB-O-SIL by Cabot Corporation of Massachusetts, U.S.A. Examples ofsuitable extending fillers include crushed quartz, aluminum oxide,magnesium oxide, calcium carbonate such as ground calcium carbonate,precipitated calcium carbonate, zinc oxide, talc, diatomaceous earth,iron oxide, clays, mica, chalk, titanium dioxide, zirconia, sand, carbonblack, graphite, or a combination thereof. Examples of extending fillersare known in the art and are commercially available, including groundquartz sold under the name MIN-U-SIL by U.S. Silica of Berkeley Springs,W. Va. Other examples of commercially available extending fillersinclude calcium carbonates sold under the name CS-11 from Imerys, G3Tfrom Huber, Pfinyl 402 from Specialty Minerals, Inc. and Omyacarb 2Tfrom Omya. The amount of the filler present in the sealant depends onvarious factors (e.g. the amount and/or type of the (I) copolymer, thetypes and/or amounts of any additional materials present in the sealant,etc.), and may be readily determined by one of skill in the art. Theexact amount of the filler employed in a specific implementation of thesealant will also depend on whether more than one type of filler isutilized. Typically, where present, the sealant comprises the filler inan amount of from 0.1 to 95, alternatively from 1 to 60, alternativelyfrom 1 to 20 wt. %, based on the weight of the sealant.

In particular embodiments, the sealant comprises a treating agent. Thetreating agent is not limited, and may be any treating agent suitablefor use in treating (e.g. surface treating) an additive of the sealant,such as the filler and other additives (e.g. physical drying agents,flame retardants, pigments, and/or water release agents) which may bepresent in the sealant. More specifically, solid and/or particulateadditives may be treated with the treating agent before being added tothe sealant. Alternatively, or in addition, solid and/or particulateadditives may be treated with the treating agent in situ. Generalexamples of suitable treating agents include those comprising analkoxysilane, an alkoxy-functional oligosiloxane, a cyclicpolyorganosiloxane, a hydroxyl-functional oligosiloxane (e.g. dimethylsiloxane or methyl phenyl siloxane), a fatty acid (e.g. a stearate, suchas calcium stearate), and the like, as well as combinations thereof.Specific examples of treating agents include alkylthiols, fatty acids,titanates, titanate coupling agents, zirconate coupling agents, and thelike, as well as combinations thereof.

In some embodiments, the treating agent is or comprises an organosiliconfiller treating agent. Examples of such organosilicon filler treatingagents include compositions suitable for treating silica fillers, suchas organochlorosilanes, organosiloxanes, organodisilazanes (e.g.hexaalkyl disilazane), and organoalkoxysilanes (e.g. CH₃Si(OCH₃)₃,C₆H₁₃Si(OCH₃)₃, C₈H₁₇Si(OC₂H₅)₃, C₁₀H₂₁Si(OCH₃)₃, C₁₂H₂₅Si(OCH₃)₃,C₁₄H₂₉Si(OC₂H₅)₃, C₆H₅CH₂CH₂Si(OCH₃)₃, etc.), and the like. In these orother embodiments, the treating agent is or comprises an alkoxysilanehaving the formula (X): R¹⁰ _(A)Si(OR¹¹)_(4-A). In formula (X),subscript A is an integer of from 1 to 3, such as 1, 2, or 3, Each R¹⁰is an independently selected monovalent organic group, such as amonovalent hydrocarbon group having from 1 to 50 carbon atoms,alternatively from 8 to 30 carbon atoms, alternatively from 8 to 18carbon atoms, alternatively from 1 to 5 carbon atoms. R¹⁰ may besaturated or unsaturated, and branched or unbranched. Alternatively, R¹⁰may be saturated and unbranched. R¹⁰ is exemplified by alkyl groups suchas methyl, ethyl, hexyl, octyl, dodecyl, tetradecyl, hexadecyl, andoctadecyl; alkenyl groups such as vinyl; and aromatic groups such asbenzyl and phenylethyl. Each R¹¹ is an independently selected saturatedhydrocarbon group having from 1 to 4 carbon atoms, alternatively from 1to 2 carbon atoms. Specific examples of organosilicon filler treatingagents also include hexyltrimethoxysilane, octyltriethoxysilane,decyltrimethoxysilane, dodecyltrimethoxysilane,tetradecyltrimethoxysilane, phenylethyltrimethoxysilane,octadecyltrimethoxysilane, octadecyltriethoxysilane, and combinationsthereof.

In some embodiments, the treating agent is or comprises analkoxy-functional oligosiloxanes. Examples of suitable alkoxy-functionaloligosiloxanes include those having the general formula (XI):(R¹²O)_(B)Si(OSiR¹³ ₂R¹⁴)_((4-B)). In formula (XI), subscript B is 1, 2or 3. In specific embodiments, subscript B is 3. Each R¹² is anindependently selected alkyl group. Each R¹³ is an independentlyselected unsaturated monovalent hydrocarbon group having from 1 to 10carbon atoms. Each R¹⁴ is an independently selected unsaturatedmonovalent hydrocarbon group having at least 10 carbon atoms.

In certain embodiments, the treating agent is or comprises apolyorganosiloxane capable of hydrogen bonding. Such treating agentsutilize multiple hydrogen bonds, which are clustered and/or dispersed,as a means to tether a compatibilization moiety to a surface of thesealant component to be treated (e.g. the filler). Suitablepolyorganosiloxanes capable of hydrogen bonding have an average, permolecule, of at least one silicon-bonded group capable of hydrogenbonding, which is typically selected from organic groups having multiplehydroxyl functionalities, organic groups having at least one aminofunctional group, and combinations thereof. In other words, thepolyorganosiloxane capable of hydrogen bonding typically utilizeshydrogen bonding as a primary mode of attachment to the filler. As such,in some embodiments, the polyorganosiloxane is incapable of formingcovalent bonds with the filler. The polyorganosiloxane may be free ofcondensable silyl groups (e.g. silicon bonded alkoxy groups, silazanes,and silanols). Examples of suitable polyorganosiloxanes for use in or asthe sealant include saccharide-siloxane polymers, amino-functionalpolyorganosiloxanes, and a combination thereof. In specific embodiments,the sealant comprises a polyorganosiloxane comprising asaccharide-siloxane polymer.

The amount of the treating agent present in the sealant depends onvarious factors (e.g. the amount and/or type of the (I) copolymer, thetypes and/or amounts of any additional materials present in the sealant(such as those treated with the treating agent), etc.), and may bereadily determined by one of skill in the art. Typically, the amount ofthe treating agent varies depending on the type of treating agentselected, the type and/or amount of particulates to be treated, andwhether the particulates are treated before being added to the sealantor in situ. Typically, where present, the sealant comprises the treatingagent in an amount of from 0.01 to 20, alternatively from 0.1 to 15,alternatively from 0.5 to 5 wt. %, based on the weight of the sealant.

In some embodiments, the sealant comprises a polymer additive, such ascrosslinkers, chain extenders, plasticizers, end-blockers, and the like,or combinations thereof. In general, suitable polymer additives includecompounds having functional groups that are reactive with functionalgroups present in the (I) copolymer of the sealant, or with functionalgroups present in another polymer additive that has been reactedtherewith. Certain polymer additives may be named based on an intendedfunction (e.g. to cross-link, to chain-extend, to end-block, etc.).However, it is to be appreciated that there may be overlap in functionsbetween types of polymer additives because certain polymer additivesdescribed herein may have more than one function as will be readilyappreciated by one of skill in the art. For examples, suitablecrosslinkers include those comprising a compound having an average, permolecule, of two or more substituents reactive with alkoxy groupspresent within the (I) copolymer, and suitable chain extenders includethose comprising a compound having an average, per molecule, of twosubstituents reactive with alkoxy groups present within the (I)copolymer or with groups present within another polymer additive reactedwith the (I) copolymer. Accordingly, as is understood by those of skillin the art, various compounds may be used as a cross-linker and/or achain extender. Similarly, various plasticizers, which are exemplifiedby the particular plasticizers described below, may also beinterchangeably utilized in or as a crosslinker and/or a chain extenderof the sealant.

In some embodiments, the sealant comprises a crosslinker. Some examplesof suitable crosslinkers include silane crosslinkers having hydrolyzablegroups, or partial or full hydrolysis products thereof. Examples of suchsilane crosslinkers include those including a silicon compound havingthe general formula (XII): R¹⁵ _(C)Si(R¹⁶)_((4-C)), where each R¹⁵ is anindependently selected monovalent hydrocarbon group, such as an alkylgroup; each R¹⁶ is a hydrolyzable substituent, for example, a halogenatom, an acetamido group, an acyloxy group such as acetoxy, an alkoxygroup, an amido group, an amino group, an aminoxy group, a hydroxylgroup, an oximo group, a ketoximo group, or a methylacetamido group; andsubscript C is 0-3, such as 0,1, 2, or 3. Typically, subscript C has anaverage value greater than 2. Alternatively, subscript C may have avalue ranging from 3 to 4. Typically, each R¹⁶ is independently selectedfrom hydroxyl, alkoxy, acetoxy, amide, or oxime. Specific examples ofsuitable silane crosslinkers include methyldiacetoxymethoxysilane,methylacetoxydimethoxysilane, vinyldiacetoxymethoxysilane,vinylacetoxydimethoxysilane, methyldiacetoxyethoxysilane,metylacetoxydiethoxysilane, and combinations thereof.

In some embodiments, the crosslinker includes an acyloxysilane, analkoxysilane, a ketoximosilane, an oximosilane, or the like, orcombinations thereof.

Examples of suitable acetoxysilane crosslinkers includetetraacetoxysilanes, organotriacetoxysilanes, diorganodiacetoxysilanes,and combinations thereof. The acetoxysilane may contain alkyl groupssuch as methyl, ethyl, propyl, isopropyl, butyl, and tertiary butyl;alkenyl groups such as vinyl, allyl, or hexenyl; aryl groups such asphenyl, tolyl, or xylyl; aralkyl groups such as benzyl or 2-phenylethyl;and fluorinated alkyl groups such as 3,3,3-trifluoropropyl. Exemplaryacetoxysilanes include tetraacetoxysilane, methyltriacetoxysilane,ethyltriacetoxysilane, vinyltriacetoxysilane, propyltriacetoxysilane,butyltriacetoxysilane, phenyltriacetoxysilane, octyltriacetoxysilane,dimethyldiacetoxysilane, phenylmethyldiacetoxysilane,vinylmethyldiacetoxysilane, diphenyl diacetoxysilane,tetraacetoxysilane, and combinations thereof. In some embodiments, thecrosslinker comprises organotriacetoxysilanes, for example mixturescomprising methyltriacetoxysilane and ethyltriacetoxysilane.

Examples of suitable aminofunctional alkoxysilanes suitable for use inor as the crosslinker are exemplified by H₂N(CH₂)₂Si(OCH₃)₃,H₂N(CH₂)₂Si(OCH₂CH₃)₃, H₂N(CH₂)₃Si(OCH₃)₃, H₂N(CH₂)₃Si(OCH₂CH₃)₃,CH₃NH(CH₂)₃Si(OCH₃)₃, CH₃NH(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₅Si(OCH₃)₃,CH₃NH(CH₂)₅Si(OCH₂CH₃)₃, H₂N(CH₂)₂NH(CH₂)₃Si(OCH₃)₃,H₂N(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃,CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃, C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃,C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃, H₂N(CH₂)₂SiCH₃(OCH₃)₂,H₂N(CH₂)₂SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₃SiCH₃(OCH₃)₂,H₂N(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₃SiCH₃(OCH₃)₂,CH₃NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₅SiCH₃(OCH₃)₂,CH₃NH(CH₂)₅SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, and combinations thereof.

Examples of suitable oximosilane crosslinkers includealkyltrioximosilanes such as methyltrioximosilane, ethyltrioximosilane,propyltrioximosilane, and butyltrioximosilane; alkoxytrioximosilanessuch as methoxytrioximosilane, ethoxytrioximosilane, andpropoxytrioximosilane; or alkenyltrioximosilanes such aspropenyltrioximosilane or butenyltrioximosilane; alkenyloximosilanessuch as vinyloximosilane; alkenylalkyldioximosilanes such as vinylmethyl dioximosilane, vinyl ethyldioximosilane, vinylmethyldioximosilane, or vinylethyldioximosilane; or combinationsthereof.

Examples of suitable ketoximosilanes crosslinkers include methyltris(dimethylketoximo)silane, methyl tris(methylethylketoximo)silane,methyl tris(methylpropylketoximo)silane, methyltris(methylisobutylketoximo)silane, ethyl tris(dimethylketoximo)silane,ethyl tris(methylethylketoximo)silane, ethyltris(methylpropylketoximo)silane, ethyltris(methylisobutylketoximo)silane, vinyl tris(dimethylketoximo)silane,vinyl tris(methylethylketoximo)silane, vinyltris(methylpropylketoximo)silane, vinyltris(methylisobutylketoximo)silane, tetrakis(dimethylketoximo)silane,tetrakis(methylethylketoximo)silane,tetrakis(methylpropylketoximo)silane,tetrakis(methylisobutylketoximo)silane,methylbis(dimethylketoximo)silane, methylbis(cyclohexylketoximo)silane,triethoxy(ethylmethylketoxime)silane,diethoxydi(ethylmethylketoxime)silane,ethoxytri(ethylmethylketoxime)silane,methylvinylbis(methylisobutylketoximo)silane, or a combination thereof.

In certain embodiments, the crosslinker comprises an alkoxysilaneexemplified by a dialkoxysilane, such as a dialkyldialkoxysilane; atrialkoxysilane, such as an alkyltrialkoxysilane; a tetraalkoxysilane;partial or full hydrolysis products thereof; or a combination thereof.Examples of suitable trialkoxysilanes include methyltrimethoxysilane,vinyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane,ethyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane,and combinations thereof. Examples of suitable tetraalkoxysilanesinclude tetraethoxysilane. In specific embodiments, the crosslinkercomprises, alternatively is, methyltrimethoxysilane.

In certain embodiments, the crosslinker is polymeric. For example, thecrosslinker may comprise a disilane such as bis(triethoxysilyl)hexane),1,4-bis[trimethoxysilyl(ethyl)]benzene, bis[3-(triethoxysilyl)propyl]tetrasulfide, bis(trimethoxysilyl)hexane), bis(triethoxysilyl)ethane,bis(trimethoxysilyl)ethane, and combinations thereof. In these or otherembodiments, the crosslinker may be one single crosslinker or acombination comprising two or more crosslinkers that differ from oneanother, e.g. based on hydrolyzable substituents and other organicgroups bonded to silicon, and, when a polymeric crosslinker is used,siloxane units, structure, molecular weight, sequence, etc.

The amount of the crosslinker present in the sealant depends on variousfactors (e.g. the amount and/or type of the (I) copolymer, the typesand/or amounts of any additional materials present in the sealant (suchas other polymer additives), the type of crosslinker utilized, etc.),and may be readily determined by one of skill in the art. In general,where present, the sealant comprises the crosslinker in an amount offrom 0.5 to 15, alternatively from 1 to 10, alternatively from 3 to 10wt. %, based on the weight of the (I) copolymer.

In some embodiments, the sealant comprises a plasticizer. Examples ofsuitable plasticizers include organic plasticizers, such as thosecomprising a carboxylic acid ester (e.g. esters), a phthalate (e.g.phthalates), a carboxylate (e.g. carboxylates), an adipate (e.g.adipates), or a combination thereof. Specific examples of suitableorganic plasticizers include bis(2-ethylhexyl)terephthalate,bis(2-ethylhexyl)-1,4-benzenedicarboxylate, 2-ethylhexylmethyl-1,4-benzenedicarboxylate, 1,2 cyclohexanedicarboxylic acid,dinonyl ester (branched and linear), bis(2-propylheptyl)phthalate,diisononyl adipate, and combinations thereof.

In certain embodiments, the plasticizer is an ester having an average,per molecule, of at least one group of formula:

where R¹⁷ represents a hydrogen atom or a monovalent organic group (e.g.a branched or linear monovalent hydrocarbon group, such as an alkylgroup of 4 to 15 carbon atoms, alternatively 9 to 12 carbon atoms). Inthese or other embodiments, the plasticizer has an average, permolecule, of at least two groups of the formula above each bonded tocarbon atoms in a cyclic hydrocarbon. In such instances, the plasticizermay have general formula:

In this formula, D is a carbocyclic group having 3 or more carbon atoms,alternatively 3 to 15 carbon atoms, which may be unsaturated, saturated,or aromatic. Subscript E is from 1 to 12. Each R¹⁸ is independently abranched or linear monovalent hydrocarbon group, such as an alkyl groupof 4 to 15 carbon atoms (e.g. an alkyl group such as methyl, ethyl,butyl, etc.). Each R¹⁹ is independently a hydrogen atom or a branched orlinear, substituted or unsubstituted, monovalent organic group. Forexample, in some embodiments, at least one R¹⁹ is a moiety comprising anester functional group.

In specific embodiments, the sealant comprises a polymeric plasticizer.Examples of polymeric plasticizers include alkenyl polymers (e.g. thoseobtained by polymerizing vinyl or allyl monomers via various methods);polyalkylene glycol esters (e.g. diethylene glycol dibenzoates,triethylene glycols, dibenzoate pentaerythritol esters, etc.); polyesterplasticizers (e.g. those obtained from dibasic acids such as sebacicacid, adipic acid, azelaic acid, phthalic acid, etc. and dihydricalcohols such as ethylene glycol, diethylene glycol, triethylene glycol,propylene glycol, dipropylene glycol, etc.); polyethers includingpolyether polyols each having a molecular weight of not less than 500(e.g. polyethylene glycols, polypropylene glycols, polytetramethyleneglycols, etc.); polystyrenes (e.g. polystyrene,poly-alpha-methylstyrene, etc.); polybutenes and polybutadienes (e.g.polyisobutylene, butadiene acrylonitrile, etc.); and polychloroprenes.In various embodiments, a low molecular weight plasticizer and a highermolecular weight polymeric plasticizer may present in the sealant incombination.

Specific plasticizers are known in the art and are commerciallyavailable. Such plasticizers may be present in the sealant alone or incombination. For example, the plasticizer may comprise a phthalate, suchas: a dialkyl phthalate such as dibutyl phthalate (Eastman™ DBPPlasticizer), diheptyl phthalate, diisononyl phthalate, di(2-ethylhexyl)phthalate, or diisodecyl phthalate (DIDP), bis(2-propylheptyl) phthalate(BASF Palatinol® DPHP), di(2-ethylhexyl) phthalate (Eastman™ DOPPlasticizer), dimethyl phthalate (Eastman™ DMP Plasticizer); diethylphthalate (Eastman™ DMP Plasticizer); butyl benzyl phthalate, andbis(2-ethylhexyl)terephthalate (Eastman™ 425 Plasticizer); adicarboxylate such as Benzyl, C7-C9 linear and branched alkyl esters, 1,2, benzene dicarboxylic acid (Ferro SANTICIZER® 261A),1,2,4-benzenetricarboxylic acid (BASF Palatinol® TOTM-I),bis(2-ethylhexyl)-1,4-benzenedicarboxylate (Eastman™ 168 Plasticizer);2-ethylhexyl methyl-1,4-benzenedicarboxylate; 1,2cyclohexanedicarboxylic acid, dinonyl ester, branched and linear (BASFHexamoll® DINCH); diisononyl adipate; trimellitates such as trioctyltrimellitate (Eastman™ TOTM Plasticizer); triethylene glycolbis(2-ethylhexanoate) (Eastman™ TEG-EH Plasticizer); triacetin (Eastman™Triacetin); nonaromatic dibasic acid esters such as dioctyl adipate,bis(2-ethylhexyl)adipate (Eastman™ DOA Plasticizer and Eastman™ DOAPlasticizer, Kosher), di-2-ethylhexyladipate (BASF Plastomoll® DOA),dioctyl sebacate, dibutyl sebacate and diisodecyl succinate; aliphaticesters such as butyl oleate and methyl acetyl recinolate; phosphatessuch as tricresyl phosphate and tributyl phosphate; chlorinatedparaffins; hydrocarbon oils such as alkyldiphenyls and partiallyhydrogenated terphenyls; process oils; epoxy plasticizers such asepoxidized soybean oil and benzyl epoxystearate;tris(2-ethylhexyl)ester; a fatty acid ester; and a combination thereof.Examples of other suitable plasticizers and their commercial sourcesinclude BASF Palamoll® 652 and Eastman 168 Xtreme™ Plasticizer.

The amount of the plasticizer present in the sealant depends on variousfactors (e.g. the amount and/or type of the (I) copolymer, the typesand/or amounts of any additional materials present in the sealant (suchas other polymer additives), the type of crosslinker utilized, etc.),and may be readily determined by one of skill in the art. In general,where present, the sealant comprises the plasticizer in an amount offrom 5 to 150 parts by weight based on the combined weights of allcomponents in the sealant. In specific embodiments, the sealantcomprises the plasticizer in an amount of from 0.1 to 10 wt. % based onthe total weight of the sealant.

In some embodiments, the sealant comprises an extender. Examples ofsuitable extenders include non-functional polyorganosiloxanes, such asthose comprising difunctional units of the formula R²⁰ ₂SiO_(2/2) andterminal units of the formula R²¹ ₃SiD′-, where each R²⁰ and each R²¹are independently a monovalent organic group such as a monovalenthydrocarbon group exemplified by alkyl such as methyl, ethyl, propyl,and butyl; alkenyl such as vinyl, allyl, and hexenyl; aryl such asphenyl, tolyl, xylyl, and naphthyl; and aralkyl groups such asphenylethyl; and D′ is an oxygen atom or a divalent group.Non-functional polyorganosiloxanes are known in the art and arecommercially available. Suitable non-functional polyorganosiloxanes areexemplified by, but not limited to, polydimethylsiloxanes. Suchpolydimethylsiloxanes include DOWSIL® 200 Fluids, which are commerciallyavailable from Dow Silicones Corporation of Midland, Mich., U.S.A. andmay have viscosity ranging from 5×10⁻⁵ to 0.1, alternatively from 5×10⁻⁵to 0.05, and alternatively from 0.0125 to 0.06, m²/s. The amount of theextender present in the sealant depends on various factors (e.g. theamount and/or type of the (I) copolymer, the types and/or amounts of anyadditional materials present in the sealant (such as other polymeradditives), the type of crosslinker utilized, etc.), and may be readilydetermined by one of skill in the art. In general, where present, thesealant comprises the extender in an amount of from 0.1 to 10 wt. %based on the total weight of the sealant.

In some embodiments, the sealant comprises an end-blocker. Suitableend-blockers comprise an M unit, i.e., a siloxane unit of formula R²²₃SiO_(1/2), where each R²² independently represents a monovalent organicgroup, such as a monovalent hydrocarbon group. General examples of suchend-blockers include those comprising a polyorganosiloxane (e.g. apolydiorganosiloxane, such as a polydimethylsiloxane) that isend-blocked at one terminus by a triorganosilyl group, e.g.(CH₃)₃SiO_(1/2), and at another terminus by a hydroxyl group. Otherexamples of suitable end-blockers include polydiorganosiloxanes havingboth hydroxyl end groups and triorganosilyl end groups, such as thosehaving more than 50%, alternatively more than 75%, of the total endgroups as hydroxyl groups. The amount of triorganosilyl group present insuch end-blockers may vary, and is typically used to regulate themodulus of the reaction product prepared by condensation reaction of thesealant. Without wishing to be bound by theory, it is thought thathigher concentrations of triorganosilyl end groups may provide a lowermodulus in certain cured products. In some embodiments, the end-blockerof the sealant comprises a single end-blocking compound. However, inother embodiments, the end-blocker of sealant comprises two or moredifferent end-blocking compounds that differ from one another, e.g. byway of properties including structure, viscosity, average molecularweight, polymer units, sequence, etc., or combinations thereof. Theamount of the end-blocker present in the sealant depends on variousfactors (e.g. the amount and/or type of the (I) copolymer, the typesand/or amounts of any additional materials present in the sealant (suchas other polymer additives), the type of end-blocker utilized, etc.),and may be readily determined by one of skill in the art. In general,where present, the sealant comprises the end-blocker in an amount offrom 0 to 50, alternatively from 0 to 30, alternatively from 0 to 15,wt. %, based on the total weight of the (I) copolymer.

In certain embodiments, the sealant comprises a surface modifier.Suitable surface modifiers include adhesion promoters, release agents,and the like, as well as combinations thereof. Typically, the surfacemodifier is utilized to change the appearance of the surface of areaction product of the sealant. For example, the surface modifier maybe used to increase gloss of the surface of such a reaction product.Specific examples of suitable surface modifiers includepolydiorganosiloxanes with alkyl and aryl groups. For example, DOWSIL®550 Fluid is a trimethylsiloxy-terminatedpoly(dimethyl/methylphenyl)siloxane with a viscosity of 0.000125 m²/sthat is commercially available from Dow Silicones Corporation. These andother examples of suitable surface modifiers include natural oils (e.g.those obtained from a plant or animal source), such as linseed oil, tungoil, soybean oil, castor oil, fish oil, hempseed oil, cottonseed oil,oiticica oil, rapeseed oil, and the like, as well as combinationsthereof.

In some embodiments, the surface modifier is an adhesion promoter.Suitable adhesion promoters may comprise a hydrocarbonoxysilane such asan alkoxysilane, a combination of an alkoxysilane and ahydroxy-functional polyorganosiloxane, an amino functional silane, anepoxy functional silane, a mercaptofunctional silane, or a combinationthereof. Adhesion promoters are known in the art and may comprisesilanes having the formula R²³ _(F)R²⁴ _(G)Si(OR²⁵)_(4−(F+G)) where eachR²³ is independently a monovalent organic group having at least 3 carbonatoms; R²⁴ contains at least one SiC bonded substituent having anadhesion-promoting group, such as amino, epoxy, mercapto or acrylategroups; each R²⁵ is independently a monovalent organic group (e.g.methyl, ethyl, propyl, butyl, etc.); subscript F has a value rangingfrom 0 to 2; subscript G is either 1 or 2; and the sum of (F+G) is notgreater than 3. In certain embodiments, the adhesion promoter comprisesa partial condensate of the above silane. In these or other embodiments,the adhesion promoter comprises a combination of an alkoxysilane and ahydroxy-functional polyorganosiloxane.

In some embodiments, the adhesion promoter comprises an unsaturated orepoxy-functional compound. In such embodiments, the adhesion promotermay be or comprise an unsaturated or epoxy-functional alkoxysilane suchas those having the formula (XIII): R²⁶ _(H)Si(OR²⁷)_((4−H)), wheresubscript H is 1, 2, or 3, alternatively subscript H is 1. Each R²⁶ isindependently a monovalent organic group with the proviso that at leastone R²⁶ is an unsaturated organic group or an epoxy-functional organicgroup. Epoxy-functional organic groups for R²⁶ are exemplified by3-glycidoxypropyl and (epoxycyclohexyl)ethyl. Unsaturated organic groupsfor R²⁶ are exemplified by 3-methacryloyloxypropyl, 3-acryloyloxypropyl,and unsaturated monovalent hydrocarbon groups such as vinyl, allyl,hexenyl, undecylenyl. Each R²⁷ is independently a saturated hydrocarbongroup of 1 to 4 carbon atoms, alternatively 1 to 2 carbon atoms. R²⁷ isexemplified by methyl, ethyl, propyl, and butyl.

Specific examples of suitable epoxy-functional alkoxysilanes include3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane,(epoxycyclohexyl)ethyldimethoxysilane,(epoxycyclohexyl)ethyldiethoxysilane and combinations thereof. Examplesof suitable unsaturated alkoxysilanes include vinyltrimethoxysilane,allyltrimethoxysilane, allyltriethoxysilane, hexenyltrimethoxysilane,undecylenyltrimethoxysilane, 3-methacryloyloxypropyl trimethoxysilane,3-methacryloyloxypropyl triethoxysilane, 3-acryloyloxypropyltrimethoxysilane, 3-acryloyloxypropyl triethoxysilane, and combinationsthereof.

In some embodiments, the adhesion promoter comprises an epoxy-functionalsiloxane, such as a reaction product of a hydroxy-terminatedpolyorganosiloxane with an epoxy-functional alkoxysilane (e.g. such asone of those described above), or a physical blend of thehydroxy-terminated polyorganosiloxane with the epoxy-functionalalkoxysilane. The adhesion promoter may comprise a combination of anepoxy-functional alkoxysilane and an epoxy-functional siloxane. Forexample, the adhesion promoter is exemplified by a mixture of3-glycidoxypropyltrimethoxysilane and a reaction product ofhydroxy-terminated methylvinylsiloxane with3-glycidoxypropyltrimethoxysilane, or a mixture of3-glycidoxypropyltrimethoxysilane and a hydroxy-terminatedmethylvinylsiloxane, or a mixture of 3-glycidoxypropyltrimethoxysilaneand a hydroxy-terminated methylvinyl/dimethylsiloxane copolymer.

In certain embodiments, the adhesion promoter comprises anaminofunctional silane, such as an aminofunctional alkoxysilaneexemplified by H₂N(CH₂)₂Si(OCH₃)₃, H₂N(CH₂)₂Si(OCH₂CH₃)₃,H₂N(CH₂)₃Si(OCH₃)₃, H₂N(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₃Si(OCH₃)₃,CH₃NH(CH₂)₃Si(OCH₂CH₃)₃, CH₃NH(CH₂)₅Si(OCH₃)₃, CH₃NH(CH₂)₅Si(OCH₂CH₃)₃,H₂N(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, H₂N(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃,CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, CH₃NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃,C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₃)₃, C₄H₉NH(CH₂)₂NH(CH₂)₃Si(OCH₂CH₃)₃,H₂N(CH₂)₂SiCH₃(OCH₃)₂, H₂N(CH₂)₂SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₃SiCH₃(OCH₃)₂,H₂N(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₃SiCH₃(OCH₃)₂,CH₃NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₅SiCH₃(OCH₃)₂,CH₃NH(CH₂)₅SiCH₃(OCH₂CH₃)₂, H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,H₂N(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,CH₃NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂, C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₃)₂,C₄H₉NH(CH₂)₂NH(CH₂)₃SiCH₃(OCH₂CH₃)₂,N-(3-(trimethoxysilyl)propyl)ethylenediamine, and the like, as well ascombinations thereof. In these or other embodiments, the adhesionpromoter comprises a mercaptofunctional alkoxysilane, such as3-mercaptopropyltrimethoxysilane or 3-mercaptopropyltriethoxysilane.

Additional examples of surface modifiers include adhesion promoterswhich are the reaction product of an epoxyalkylalkoxysilane, such as3-glycidoxypropyltrimethoxysilane, and an amino-substitutedalkoxysilane, such as 3-aminopropyltrimethoxysilane, optionally with analkylalkoxysilane, such as methyltrimethoxysilane.

In some embodiments, the surface modifier comprises, alternatively is, arelease agent. Suitable release agents are exemplified by fluorinatedcompounds, such as fluoro-functional silicones, or fluoro-functionalorganic compounds. In specific embodiments, the sealant comprisesmultiple surface modifiers, such as one or more adhesion promoters, oneor more release agents, one or more natural oils, or combinationsthereof.

The amount of the surface modifier present in the sealant depends onvarious factors (e.g. the amount and/or type of the (I) copolymer, thetypes and/or amounts of any additional materials present in the sealant,curing conditions to which the sealant is intended to be exposed, etc.),and may be readily determined by one of skill in the art. In general,where present, the sealant comprises the surface modifier in an amountof from 0.01 to 50, alternatively from 0.01 to 10, alternatively from0.01 to 5 parts by weight, based on the combined weights of allcomponents in the sealant.

In certain embodiments, the sealant comprises a drying agent, such asphysical drying agents (e.g. adsorbents), chemical drying agents, etc.In general, the drying agent binds water and low-molecular weightalcohol from various sources. For example, the drying agent may bindby-products of a condensation reaction involving the (I) copolymer, suchas water and alcohols. Physical drying agents typically trap and/oradsorb such water and/or by-products, where chemical drying agentstypically binding the water and/or other by-products by chemical means(e.g. via covalent bonding). Examples of suitable drying agents for usein the sealant include adsorbents, such as those comprising inorganicparticulates. Such adsorbents typically have a particle size of 10micrometers or less, alternatively 5 micrometers or less, and an averagepore size sufficient to adsorb water and low-molecular weight alcoholalcohols (e.g. an average pore size of 10 Å (Angstroms) or less,alternatively 5 Å or less, alternatively 3 Å or less). Specific examplesof such adsorbents include zeolites (e.g. chabasite, mordenite, andanalcite) and molecular sieves comprising alkali metal aluminosilicates, silica gel, silica-magnesia gel, activated carbon, activatedalumina, calcium oxide, and combinations thereof. Examples ofcommercially available drying agents include dry molecular sieves, suchas 3 Å (Angstrom) molecular sieves sold under the trademark SYLOSIV® byGrace Davidson and under the trade name PURMOL by Zeochem of Louisville,Ky., U.S.A., and 4 Å molecular sieves sold under the trade name Doucilzeolite 4 Å by Ineos Silicas of Warrington, England. Other examples ofsuitable drying agents include: MOLSIV ADSORBENT TYPE 13X, 3A, 4A, and 5Å molecular sieves, all of which are commercially available from UOP ofIllinois, U.S.A.; SILIPORITE NK 30AP and 65×P molecular sieves fromAtofina of Philadelphia, Pa., U.S.A.; and molecular sieves availablefrom W.R. Grace of Maryland, U.S.A. under various names. Examples ofchemical drying agents include silanes, such as those described abovewith respect to the crosslinker. For example, alkoxysilanes suitable asdrying agents include vinyltrimethoxysilane, vinyltriethoxysilane, andcombinations thereof. As understood by those of skill in the art, thechemical drying agent may be added to the sealant, or to a part of thesealant (e.g. where the sealant is a multiple-part composition) to keepthe sealant or part thereof free from water. As such, the drying agentmay be added to a part (e.g. a dry part) of the sealant prior to thesealant being formed, thereby rendering the part shelf stable.Alternatively, or additionally, the drying agent may keep the sealantfree from water after formulation (e.g. after the parts of the sealantare combined/mixed together). The amount of the drying agent present inthe sealant depends on various factors (e.g. the amount and/or type ofthe (I) copolymer, the types and/or amounts of any additional materialspresent in the sealant, curing conditions to which the sealant isintended to be exposed, etc.), and may be readily determined by one ofskill in the art. In general, where present, the sealant comprises thedrying agent in an amount of from 0.1 to 5 parts by weight, based on thecombined weights of all components in the sealant.

In some embodiments, the sealant comprises a biocide. General examplesof suitable biocides include fungicides, herbicides, pesticides,antimicrobials, and the like, as well as combinations thereof. Forexample, in certain embodiments, the biocide comprises, alternativelyis, a fungicide. Specific examples of the fungicide includeN-substituted benzimidazole carbamates and benzimidazolyl carbamates,such as methyl 2-benzimidazolylcarbamate, ethyl2-benzimidazolylcarbamate, isopropyl 2-benzimidazolylcarbamate, methylN-{2-[1-(N,N-dimethylcarbamoyl)benzimidazolyl]}carbamate, methylN-{2-[1-(N,N-dimethylcarbamoyl)-6-methylbenzimidazolyl]}carbamate,methylN-{2-[1-(N,N-dimethylcarbamoyl)-5-methylbenzimidazolyl]}carbamate,methyl N-{2-[1-(N-methylcarbamoyl)benzimidazolyl]}carbamate, methylN-{2-[1-(N-methylcarbamoyl)-6-methylbenzimidazolyl]}carbamate, methylN-{2-[1-(N-methylcarbamoyl)-5-methylbenzimidazolyl]}carbamate, ethylN-{2-[1-(N,N-dimethylcarbamoyl)benzimidazolyl]}carbamate, ethylN-{2-[2-(N-methylcarbamoyl)benzimidazolyl]}carbamate, ethylN-{2-[1-(N,N-dimethylcarbamoyl)-6-methylbenzimidazolyl]}carbamate, ethylN-{2-[1-(N-methylcarbamoyl)-6-methylbenzimidazolyl]}carbamate, isopropylN-{2-[1-(N,N-dimethylcarbamoyl)benzimidazolyl]}carbamate, isopropylN-{2-[1-(N-methylcarbamoyl)benzimidazolyl]}carbamate, methylN-{2-[1-(N-propylcarbamoyl)benzimidazolyl]}carbamate, methylN-{2-[1-(N-butylcarbamoyl)benzimidazolyl]}carbamate, methoxyethylN-{2-[1-(N-propylcarbamoyl)benzimidazolyl]}carbamate, methoxyethylN-{2-[1-(N-butylcarbamoyl)benzimidazolyl]}carbamate, ethoxyethylN-{2-[1-(N-propylcarbamoyl)benzimidazolyl]}carbamate, ethoxyethylN-{2-[1-(N-butylcarbamoyl)benzimidazolyl]}carbamate, methylN-{1-(N,N-dimethylcarbamoyloxy)benzimidazolyl]}carbamate, methylN-{2-[N-methylcarbamoyloxy)benzimidazolyl]}carbamate, methylN-{2-[1-(N-butylcarbamoyloxy)benzoimidazolyl]}carbamate, ethoxyethylN-{2-[1-(N-propylcarbamoyl)benzimidazolyl]}carbamate, ethoxyethylN-{2-[1-(N-butylcarbamoyloxy)benzoimidazolyl]}carbamate, methylN-{2-[1-(N,N-dimethylcarbamoyl)-6-chlorobenzimidazolyl]}carbamate, andmethyl N-{2-[1-(N,N-dimethylcarbamoyl)-6-nitrobenzimidazolyl]}carbamate;10,10′-oxybisphenoxarsine (trade name: Vinyzene, OBPA);di-iodomethyl-para-tolylsulfone;benzothiophene-2-cyclohexylcarboxamide-S,S-dioxide;N-(fluordichloridemethylthio)phthalimide (trade names: Fluor-Folper,Preventol A3); methyl-benzimideazol-2-ylcarbamate (trade names:Carbendazim, Preventol BCM); Zinc-bis(2-pyridylthio-1-oxide); zincpyrithione; 2-(4-thiazolyl)-benzimidazol;N-phenyl-iodpropargylcarbamate; N-octyl-4-isothiazolin-3-on;4,5-dichloride-2-n-octyl-4-isothiazolin-3-on;N-butyl-1,2-benzisothiazolin-3-on; triazolyl-compounds, such astebuconazol; and the like, as well as combinations thereof. Inparticular embodiments, such fungicides are utilized in combination withone or more inorganic materials, such as mineral (e.g. zeolites), metals(e.g. copper, silver, platinum, etc.), and combinations thereof.

In particular embodiments, the biocide comprises, alternatively is, anherbicide. Specific examples of the herbicide include amide herbicidessuch as allidochlor N,N-diallyl-2-chloroacetamide; CDEA2-chloro-N,N-diethylacetamide; etnipromid(RS)-2-[5-(2,4-dichlorophenoxy)-2-nitrophenoxy]-N-ethylpropionamide;anilide herbicides such as cisanilidecis-2,5-dimethylpyrrolidine-1-carboxanilide; flufenacet4′-fluoro-N-isopropyl-2-[5-(trifluoromethyl)-1,3,4-thiadiazol-2-yloxy]acetanilide;naproanilide (RS)-α-2-naphthoxypropionanilide; arylalanine herbicidessuch as benzoylprop N-benzoyl-N-(3,4-dichlorophenyl)-DL-alanine;flamprop-M N-benzoyl-N-(3-chloro-4-fluorophenyl)-D-alanine;chloroacetanilide herbicides such as butachlor N-butoxymethyl-2-chloro-2′,6′-diethylacetanilide; metazachlor2-chloro-N-(pyrazol-1-ylmethyl)acet-2′,6′-xylidide; prynachlor(RS)-2-chloro-N-(1-methylprop-2-ynyl)acetanilide; sulphonanilideherbicides such as cloransulam3-chloro-2-(5-ethoxy-7-fluoro[1,2,4]triazolo[1,5-c]pyrimidin-2-ylsulphonamido)benzoicacid; metosulam2′,6′-dichloro-5,7-dimethoxy-3′-methyl[1,2,4]triazolo[1,5-a]pyrimidine-2-sulphonanilide;antibiotic herbicides such as bilanafos4-[hydroxy(methyl)phosphinoyl]-L-homoalanyl-L-alanyl-L-alanine; benzoicacid herbicides such as chloramben 3-amino-2,5-dichlorobenzoic acid;2,3,6-TBA 2,3,6-trichlorobenzoic acid; pyrimidinyloxybenzoic acidherbicides such as bispyribac2,6-bis(4,6-dimethoxypyrimidin-2-yloxy)benzoic acid;pyrimidinylthiobenzoic acid herbicides such as pyrithiobac2-chloro-6-(4,6-dimethoxypyrimidin-2-ylthio)benzoic acid; phthalic acidherbicides such as chlorthal tetrachloroterephthalic acid; picolinicacid herbicides such as aminopyralid4-amino-3,6-dichloropyridine-2-carboxylic acid; quinolinecarboxylic acidherbicides such as quinclorac 3,7-dichloroquinoline-8-carboxylic acid;arsenical herbicides such as CMA calcium bis(hydrogen methylarsonate);MAMA ammonium hydrogen methylarsonate; sodium arsenite;benzoylcyclohexanedione herbicides such as mesotrione2-(4-mesyl-2-nitrobenzoyl)cyclohexane-1,3-dione; benzofuranylalkylsulphonate herbicides such as benfuresate2,3-dihydro-3,3-dimethylbenzofuran-5-yl ethanesulphonate; carbamateherbicides such as carboxazole methyl5-tert-butyl-1,2-oxazol-3-ylcarbamate; fenasulam methyl4-[2-(4-chloro-o-tolyloxy)acetamido]phenylsulphonylcarbamate;carbanilate herbicides such as BCPC (RS)-sec-butyl 3-chlorocarbanilate;desmedipham ethyl 3-phenylcarbamoyloxyphenylcarbamate; swep methyl3,4-dichlorocarbanilate; cyclohexene oxime herbicides such as butroxydim(RS)-(EZ)-5-(3-butyryl-2,4,6-trimethylphenyl)-2-(1-ethoxyiminopropyl)-3-hydroxycyclohex-2-en-1-one;tepraloxydim(RS)-(EZ)-2-{1-[(2E)-3-chloroallyloxyimino]propyl}-3-hydroxy-5-perhydropyran-4-ylcyclohex-2-en-1-one;cyclopropylisoxazole herbicides such as isoxachlortole4-chloro-2-mesylphenyl 5-cyclopropyl-1,2-oxazol-4-yl ketone;dicarboximide herbicides such as flumezin2-methyl-4-(α,α,α-trifluoro-m-tolyl)-1,2,4-oxadiazinane-3,5-dione;dinitroaniline herbicides such as ethalfluralinN-ethyl-α,α,α-trifluoro-N-(2-methylallyl)-2,6-dinitro-p-toluidine;prodiamine 5-dipropylamino-α,α,α-trifluoro-4,6-dinitro-o-toluidine;dinitrophenol herbicides such as dinoprop 4,6-dinitro-o-cymen-3-ol;etinofen α-ethoxy-4,6-dinitro-o-cresol; diphenyl ether herbicides suchas ethoxyfenO-[2-chloro-5-(2-chloro-α,α,α-trifluoro-p-tolyloxy)benzoyl]-L-lacticacid; nitrophenyl ether herbicides such as aclonifen2-chloro-6-nitro-3-phenoxyaniline; nitrofen 2,4-dichlorophenyl4-nitrophenyl ether; dithiocarbamate herbicides such as dazomet3,5-dimethyl-1,3,5-thiadiazinane-2-thione; halogenated aliphaticherbicides such as dalapon 2,2-dichloropropionic acid; chloroaceticacid; imidazolinone herbicides such as imazapyr(RS)-2-(4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl)nicotinic acid;inorganic herbicides such as disodium tetraborate decahydrate; sodiumazide; nitrile herbicides such as chloroxynil3,5-dichloro-4-hydroxybenzonitrile; ioxynil4-hydroxy-3,5-di-iodobenzonitrile; organophosphorus herbicides such asanilofos S-4-chloro-N-isopropylcarbaniloylmethyl O,O-dimethylphosphorodithioate; glufosinate4-[hydroxy(methyl)phosphinoyl]-DL-homoalanine; phenoxy herbicides suchas clomeprop (RS)-2-(2,4-dichloro-m-tolyloxy)propionanilide; fenteracol2-(2,4,5-trichlorophenoxy)ethanol; phenoxyacetic herbicides such as MCPA(4-chloro-2-methylphenoxy)acetic acid; phenoxybutyric herbicides such asMCPB 4-(4-chloro-o-tolyloxy)butyric acid; phenoxypropionic herbicidessuch as fenoprop (RS)-2-(2,4,5-trichlorophenoxy)propionic acid;aryloxyphenoxypropionic herbicides such as isoxapyrifop(RS)-2-[2-[4-(3,5-dichloro-2-pyridyloxy)phenoxy]propionyl]isoxazolidine;phenylenediamine herbicides such as dinitramineN1,N1-diethyl-2,6-dinitro-4-trifluoromethyl-m-phenylenediamine,pyrazolyloxyacetophenone herbicides such as pyrazoxyfen2-[4-(2,4-dichlorobenzoyl)-1,3-dimethylpyrazol-5-yloxy]acetophenone;pyrazolylphenyl herbicides such as pyraflufen2-chloro-5-(4-chloro-5-difluoromethoxy-1-methylpyrazol-3-yl)-4-fluorophenoxyaceticacid; pyridazine herbicides such as pyridafol6-chloro-3-phenylpyridazin-4-ol; pyridazinone herbicides such aschloridazon 5-amino-4-chloro-2-phenylpyridazin-3(2H)-one; oxapyrazon5-bromo-1,6-dihydro-6-oxo-1-phenylpyridazin-4-yloxamic acid; pyridineherbicides such as fluoroxypyr4-amino-3,5-dichloro-6-fluoro-2-pyridyloxyacetic acid; thiazopyr methyl2-difluoromethyl-5-(4,5-dihydro-1,3-thiazol-2-yl)-4-isobutyl-6-trifluoromethylnicotinate;pyrimidinediamine herbicides such as iprymidam6-chloro-N4-isopropylpyrimidine-2,4-diamine; quaternary ammoniumherbicides such as diethamquat1,1′-bis(diethylcarbamoylmethyl)-4,4′-bipyridinium; paraquat1,1′-dimethyl-4,4′-bipyridinium; thiocarbamate herbicides such ascycloate S-ethyl cyclohexyl(ethyl)thiocarbamate; tiocarbazil S-benzyldi-sec-butylthiocarbamate; thiocarbonate herbicides such as EXDO,O-diethyl dithiobis(thioformate); thiourea herbicides such asmethiuron 1,1-dimethyl-3-m-tolyl-2-thiourea; triazine herbicides such astriaziflam(RS)-N-[2-(3,5-dimethylphenoxy)-1-methylethyl]-6-(1-fluoro-1-methylethyl)-1,3,5-triazine-2,4-diamine;chlorotriazine herbicides such as cyprazine6-chloro-N2-cyclopropyl-N4-isopropyl-1,3,5-triazine-2,4-diamine;propazine 6-chloro-A2,N4-di-isopropyl-1,3,5-triazine-2,4-diamine;methoxytriazine herbicides such as prometonN2,N4-di-isopropyl-6-methoxy-1,3,5-triazine-2,4-diamine;methylthiotriazine herbicides such as cyanatryn2-(4-ethylamino-6-methylthio-1,3,5-triazin-2-ylamino)-2-methylpropionitrile;triazinone herbicides such as hexazinone3-cyclohexyl-6-dimethylamino-1-methyl-1,3,5-triazine-2,4(1H,3H)-dione;triazole herbicides such as epronazN-ethyl-N-propyl-3-propylsulphonyl-1H-1,2,4-triazole-1-carboxamide;triazolone herbicides such as carfentrazone(RS)-2-chloro-3-{2-chloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]-4-fluorophenyl}propionicacid; triazolopyrimidine herbicides such as florasulam2′,6′,8-trifluoro-5-methoxy[1,2,4]triazolo[1,5-c]pyrimidine-2-sulphonanilide;uracil herbicides such as flupropacil isopropyl2-chloro-5-(1,2,3,6-tetrahydro-3-methyl-2,6-dioxo-4-trifluoromethylpyrimidin-1-yl)benzoate;urea herbicides such as cycluron 3-cyclo-octyl-1,1-dimethylurea;monisouron 1-(5-tert-butyl-1,2-oxazol-3-yl)-3-methylurea; phenylureaherbicides such as chloroxuron3-[4-(4-chlorophenoxy)phenyl]-1,1-dimethylurea; siduron1-(2-methylcyclohexyl)-3-phenylurea; pyrimidinylsulphonylurea herbicidessuch as flazasulphuron1-(4,6-dimethoxypyrimidin-2-yl)-3-(3-trifluoromethyl-2-pyridylsulphonyl)urea;pyrazosulphuron5-[(4,6-dimethoxypyrimidin-2-ylcarbamoyl)sulphamoyl]-1-methylpyrazole-4-carboxylicacid; triazinylsulphonylurea herbicides such as thifensulphuron3-(4-methoxy-6-methyl-1,3,5-triazin-2-ylcarbamoylsulphamoyl)thiophene-2-carboxylicacid; thiadiazolylurea herbicides such as tebuthiuron1-(5-tert-butyl-1,3,4-thiadiazol-2-yl)-1,3-dimethylurea; and/orunclassified herbicides such as chlorfenac (2,3,6-trichlorophenyl)aceticacid; methazole2-(3,4-dichlorophenyl)-4-methyl-1,2,4-oxadiazolidine-3,5-dione; tritac(RS)-1-(2,3,6-trichlorobenzyloxy)propan-2-ol; 2,4-D, chlorimuron, andfenoxaprop; and the like, as well as combinations thereof.

In some embodiments, the biocide comprises, alternatively is, apesticide. General examples of the pesticide include insect repellentssuch as N,N-diethyl-meta-toluamide, and pyrethroids such as pyrethrin.Specific examples of the pesticide include atrazine, diazinon, andchlorpyrifos. In these or other embodiments, the biocide comprises,alternatively is, an antimicrobial agent. The type and nature of theantimicrobial agent may vary, and can be readily determined by one ofskill in the art. Specific antimicrobial agents are commerciallyavailable, and include DOWSIL® 5700 and DOWSIL® 5772, which are from DowSilicones Corporation of Midland, Mich., U.S.A. In certain embodiments,the biocide comprises, alternatively is, a boron-containing material,such as a boric anhydride, borax, or a disodium octaborate tetrahydrate.In various embodiments, the sealant comprises two or more biocides,which are each independently selected from the fungicide, herbicidepesticide, antimicrobial, and other biocidal components exemplifiedherein.

The amount of the biocide present in the sealant depends on variousfactors (e.g. the type of biocide(s) utilized, the amount and/or type ofthe (I) copolymer, an intended use of the sealant, curing conditions towhich the sealant is intended to be exposed, etc.), and may be readilydetermined by one of skill in the art. In general, where present, thesealant comprises the biocide, or a combination of biocides, in anamount of from 0.01 to 10, alternatively from 0.1 to 5 wt. % based onthe total weight of the sealant.

In particular embodiments, the sealant comprises a flame retardant.Examples of suitable flame retardants include organic/carbonaceous flameretardants (e.g. carbon black, etc.), inorganic/mineral-based flameretardants (e.g. hydrated aluminum hydroxide, silicates such aswollastonite, metal complexes of platinum and/or platinum, etc.) and thelike, as well as combinations thereof. Additional examples of suitableflame retardants include halogen-based flame retardants, such asdecabromodiphenyloxide, octabromordiphenyl oxide,hexabromocyclododecane, decabromobiphenyl oxide, diphenyoxybenzene,ethylene bis-tetrabromophthalmide, pentabromoethyl benzene,pentabromobenzyl acrylate, tribromophenyl maleic imide,tetrabromobisphenyl A, bis-(tribromophenoxy)ethane,bis-(pentabromophenoxy)ethane, polydibomophenylene oxide,tribromophenylallyl ether, bis-dibromopropyl ether, tetrabromophthalicanhydride, dibromoneopentyl gycol, dibromoethyl dibromocyclohexane,pentabromodiphenyl oxide, tribromostyrene, pentabromochlorocyclohexane,tetrabromoxylene, hexabromocyclododecane, brominated polystyrene,tetradecabromodiphenoxybenzene, trifluoropropene, and PVC; phosphorusbased flame-retardants, such as (2,3-dibromopropyl)-phosphate,phosphorus, cyclic phosphates, triaryl phosphates, bis-melaminiumpentate, pentaerythritol bicyclic phosphate, dimethylmethylphosphate,phosphine oxide diol, triphenyl phosphate,tris-(2-chloroethyl)phosphate, phosphate esters such as tricreyl-,trixylenyl-, isodecyl diphenyl-, ethylhexyl diphenyl-, trioctyl-,tributyl-, and tris-butoxyethyl phosphate esters, and phosphate salts ofvarious amines (e.g. ammonium phosphate); tetraalkyl lead compounds,such as tetraethyl lead; iron pentacarbonyl; manganese methylcyclopentadienyl tricarbonyl; melamine and derivatives thereof, such asmelamine salts; guanidine; dicyandiamide; ammonium sulphamate; aluminatrihydrate; magnesium hydroxide alumina trihydrate; and the like, aswell as derivatives, modifications, and combinations thereof. The amountof the flame retardant present in the sealant depends on various factors(e.g. the amount and/or type of the (I) copolymer, an intended use ofthe sealant, curing conditions to which the sealant is intended to beexposed, a presence/absence of a vehicle/solvent, etc.), and may bereadily determined by one of skill in the art. In general, wherepresent, the sealant comprises the flame retardant in an amount of from0.01 to 15, alternatively from 0.1 to 10 wt. % based on the total weightof the sealant.

In certain embodiments, the sealant comprises a binder. Typically, thebinder is a non-reactive, elastomeric, organic polymer, i.e., anelastomeric organic polymer that does not react with the (I) copolymer.Additionally, the binder is typically compatible with the (I) copolymer,i.e., the binder does not form a two-phase system when formulated intothe sealant with the (I) copolymer. In general, suitable binders havelow gas and moisture permeability, and typically comprise a numberaverage molecular weight (Mn) of from 30,000 to 75,000. However, thebinder may comprise a blend of various non-reactive, elastomeric,organic polymers (e.g. of such polymers having a high molecular weightwith those having a low molecular weight). In such instances, the highermolecular weight polymer(s) typically comprise a Mn of from 100,000 to600,000, and the lower molecular weight polymer(s) typically comprise aMn of from 900 to 10,000, alternatively 900 to 3,000. The value for thelower end of the Mn ranges is typically selected such that the binder iscompatible with the (I) copolymer and the other ingredients of thesealant, as understood by those of skill in the art. The binder maycomprise or be one non-reactive, elastomeric, organic polymer or,alternatively may comprise two or more non-reactive, elastomeric,organic polymers that differ from one another, e.g. on a basis ofstructure, viscosity, average molecular weight (Mn or Mw), polymerunits, sequence, etc., or combinations thereof.

Examples of suitable binders include polyisobutylenes, which are knownin the art and are commercially available. Specific examples ofpolyisobutylenes include those marketed under the trademark OPPANOL® byBASF Corporation of Germany, as well as the various grades ofhydrogenated polyisobutene marketed under the trademark PARLEAM® by NOFCorp. of Japan. Additional examples of suitable polyisobutylenes arecommercially available from ExxonMobil Chemical Co. of Baytown, Tex.,U.S.A. under the trademark VISTANEX®. These include VISTANEX® MML-80,MML-100, MML-120, and MML-140, which are paraffinic hydrocarbonpolymers, composed of long, straight-chain macromolecules containingonly chain-end olefinic bonds. VISTANEX® MM polyisobutylenes have aviscosity average molecular weight of from 70,000 to 90,000, andVISTANEX® LM polyisobutylenes (e.g. LM-MS) are lower-molecular weightpolyisobutylenes having a viscosity average molecular weight of from8,700 to 10. Additional examples of polyisobutylenes include VISTANEXLM-MH (viscosity average molecular weight of 10,000 to 11,700); SoltexPB-24 (Mn 950), Indopol® H-100 (Mn 910), Indopol® H-1200 (Mn 2100), fromAmoco Corp. of Chicago, Ill., U.S.A.; NAPVIS® and HYVIS® (e.g. NAPVIS®200, D10, and DE3; and HYVIS® 200.) from BP Chemicals of London,England. The NAPVIS® polyisobutylenes typically have a Mn of from 900 to1300. In addition, or as an alternative, to the polyisobutylene(s), thebinder may comprise or be a butyl rubber, astyrene-ethylene/butylene-styrene (SEBS) block copolymer, astyrene-ethylene/propylene-styrene (SEPS) block copolymer, polyolefinplastomer, or combinations thereof. SEBS and SEPS block copolymers areknown in the art and are commercially available as Kraton® G polymersfrom Kraton Polymers U.S. LLC of Houston, Tex., U.S.A., and as Septonpolymers from Kuraray America, Inc., New York, N.Y., U.S.A. Polyolefinplastomers are also known in the art and are commercially available asAFFINITY® GA 1900 and AFFINITY® GA 1950 compositions from Dow ChemicalCompany, Elastomers & Specialty Products Division, Midland, Mich.,U.S.A.

The amount of the binder present in the sealant depends on variousfactors (e.g. the amount and/or type of the (I) copolymer, an intendeduse of the sealant, curing conditions to which the sealant is intendedto be exposed, a presence/absence of a vehicle/solvent, etc.), and maybe readily determined by one of skill in the art. In general, wherepresent, the sealant comprises the binder in an amount of from 1 to 50,alternatively from 5 to 40, alternatively from 5 to 35 parts by weight,based on the combined weights of all components in the sealant.

In some embodiments, the sealant comprises an anti-aging additive.Examples of anti-aging additives include antioxidants, UV absorbers, UVand/or light stabilizers, heat stabilizers, and combinations thereof.The anti-aging additive may be or comprise but one anti-aging additiveor, alternatively, may comprise two or more different anti-agingadditives. Moreover, one particular anti-aging additive may servemultiple functions (e.g. as both a UV absorber and a UV stabilizer, asboth an antioxidant and a UV absorber, etc.). Many suitable anti-agingadditives are known in the art and are commercially available. Forexample, suitable antioxidants include phenolic antioxidants (e.g.fully-sterically hindered phenols and partially-hindered phenols) andcombinations of phenolic antioxidants with stabilizers (e.g. stericallyhindered amines, such as tetramethyl-piperidine derivatives, also knownas “hindered amine light stabilizers” (HALS)). Suitable phenolicantioxidants include vitamin E and IRGANOX® 1010 from BASF. IRGANOX®1010 comprises pentaerythritoltetrakis(3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate). Examples of UVabsorbers include phenol, 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methyl-,branched and linear (TINUVIN® 571). Examples of UV stabilizers includebis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate; methyl1,2,2,6,6-pentamethyl-4-piperidyl/sebacate; and combinations thereof(TINUVIN® 272). These and other TINUVIN® additives, such as TINUVIN® 765are commercially available from BASF. Other UV and light stabilizers arecommercially available, and are exemplified by LowLite from Chemtura,OnCap from PolyOne, and Light Stabilizer 210 from E. I. du Pont deNemours and Company of Delaware, U.S.A. Oligomeric (higher molecularweight) stabilizers may also be utilized in or as the anti-agingadditive, for example, to minimize potential for migration of theanti-aging additive out of the sealant or a cured product thereof.Example of such oligomeric antioxidant stabilizers include TINUVIN® 622,which is a dimethylester of butanedioic acid copolymerized with4-hydroxy-2,2,6,6-tetramethyl-1-piperidine ethanol. Examples of heatstabilizers include iron oxides, carbon blacks, iron carboxylate salts,cerium hydrates, barium zirconates, cerium and zirconium octoates,porphyrins, and the like, as well as combinations thereof.

The amount of the anti-aging additive present in the sealant depends onvarious factors (e.g. the amount and/or type of the (I) copolymer, anintended use of the sealant, curing conditions to which the sealant isintended to be exposed, etc.), and may be readily determined by one ofskill in the art. In general, where present, the sealant comprises theanti-aging additive in an amount of from greater than 0 to 5,alternatively from 0.1 to 4, alternatively from 0.5 to 3 wt. %, based onthe total weight of the sealant.

In certain embodiments, the sealant comprises a water release agent,i.e., a component that releases water over time (e.g. in response to anapplied condition, such as a temperature and/or a pressure). Typically,the water release agent contains an amount of water sufficient topartially, alternatively fully, react the sealant, and is thus selectedto release the amount of water when exposed to the applied condition(e.g. a use temperature of the sealant) for a sufficient amount of time.Generally, however the water release agent is selected to sufficientlybind the water to thereby prevent too much water from being releasedduring making and/or storing the sealant. For example, the water releaseagent typically binds the water sufficiently duringcompounding/formulating the sealant, such that sufficient water isavailable for condensation reaction of the (I) copolymer during or afterthe application process in which the sealant is used. This “controlledrelease” property also may provide the benefit of preventing too muchwater from being released and/or water being released too rapidly duringthe application process, since this may cause bubbling or voiding in thereaction product formed by condensation reaction of the (I) copolymer ofthe sealant. The particular water release agent selected can depend onvarious factors, (e.g. the other components of the sealant, theamount/type of the (I) copolymer, the type of the (II) condensationreaction catalyst, the process conditions under which the sealant willbe formulated, etc.) and will be readily determined by one of skill inthe art. Examples of suitable water release agents are exemplified bymetal salt hydrates, hydrated molecular sieves, and precipitatedcarbonates. Particular examples include the precipitated calciumcarbonate available from Solvay under the trademark WINNOFIL® SPM. Incertain embodiments, the water release agent is selected to include,alternatively to be, precipitated calcium carbonate. The water releaseagent may be selected to ensure that not all of the water content isreleased during compounding, while still releasing a sufficient amountof water for condensation reaction of the (I) copolymer when exposed tothe application temperature range for a sufficient period of time. Theamount of the water release agent present in the sealant depends onvarious factors (e.g. the water permeability of the (I) copolymer, apresence/absence of vehicle/solvent, a presence/absence of drying agent,the method by which the sealant is to be formulated/prepared, etc.), andmay be readily determined by one of skill in the art. In general, wherepresent, the sealant comprises the water release agent in an amount offrom 1 to 50, alternatively from 5 to 40, alternatively from 5 to 30parts by weight, based on the combined weights of all components in thesealant.

In some embodiments, the sealant comprises a pigment (i.e., a componentthat imparts color to the sealant and/or a reaction product thereof).Such pigments may comprise any inorganic compounds, for example those ofmetals such as chromium oxides, titanium oxides, cobalt pigments, aswell as those that are not based on such metals, e.g. non-metalinorganic compounds. Examples of suitable pigments include indigos,titanium dioxides, carbon blacks, and combinations thereof, as well asother commercially available pigments such as Stan-Tone 505P01 Green,which is available from PolyOne. In certain embodiments, the pigmentcomprises a carbon black. Specific examples of carbon blacks includeShawinigan Acetylene black, which is commercially available from ChevronPhillips Chemical Company LP; SUPERJET® Carbon Black (e.g. LB-1011)supplied by Elementis Pigments Inc., of Fairview Heights, Ill. U.S.A.;SR 511 supplied by Sid Richardson Carbon Co, of Akron, Ohio U.S.A.; andN330, N550, N762, N990 (from Degussa Engineered Carbons of Parsippany,N.J., U.S.A.). The amount of the pigment present in the sealant dependson various factors (e.g. the amount and/or type of the (I) copolymer, anintended use of the sealant, a presence/absence of a vehicle/solvent,etc.), and may be readily determined by one of skill in the art. Ingeneral, where present, the sealant comprises the pigment in an amountof from greater than 0 to 20, alternatively from 0.001 to 10,alternatively from 0.001 to 5 wt. % based on the total weight of thesealant.

In certain embodiments, the sealant comprises a rheology additive, suchas a rheology modifier and/or a viscosity modifier. Examples of suitablerheological additives include waxes; polyamides; polyamide waxes;hydrogenated castor oil derivatives; metal soaps, such as calcium,aluminum, and/or barium stearates; and the like, as well as derivatives,modifications, and combinations thereof. In particular embodiments, therheology modifier is selected to facilitate incorporation of fillers,compounding, de-airing, and/or mixing of the sealant (e.g. duringpreparation thereof), as well understood by those of skill in the art.Specific examples of rheological additives include those known in theart which are commercially available. Examples of such rheologicaladditives include Polyvest, which is commercially available from Evonik;Disparlon which is commercially available from King Industries; KevlarFibre Pulp, which is commercially available from Du Pont; Rheospan whichis commercially available from Nanocor; Ircogel, which is commerciallyavailable from Lubrizol; Crayvallac® SLX, which is commerciallyavailable from Palmer Holland, and the like, as well as combinationsthereof.

In some embodiments, the rheology modifier comprises, alternatively is,a wax (e.g. a paraffin wax, a microcrystalline wax, or a combinationthereof). The wax typically comprises non-polar hydrocarbon(s), whichmay comprise branched structures, cyclic structures, or combinationsthereof. Examples of suitable waxes include petroleum microcrystallinewaxes available from Strahl & Pitsch, Inc., of West Babylon, N.Y.,U.S.A. under the names SP 96 (melting point of from 62 to 69° C.), SP 18(melting point of from 73 to 80° C.), SP 19 (melting point of from 76 to83° C.), SP 26 (melting point ranging from 76 to 83° C.), SP 60 (meltingpoint of from 79 to 85° C.), SP 617 (melting point of from 88 to 93°C.), SP 89 (melting point of from 90 to 95° C.), and SP 624 (meltingpoint of from 90 to 95° C.). Further examples of suitable waxes includethose marketed under the trademark Multiwax® by Crompton Corporation ofPetrolia, Pa., U.S.A. Such waxes include which include Multiwax® 180-W,which comprises saturated branched and cyclic non-polar hydrocarbons andhas melting point of from 79 to 87° C.; Multiwax® W-445, which comprisessaturated branched and cyclic non-polar hydrocarbons, and has meltingpoint of from 76 to 83° C.; and Multiwax® W-835, which comprisessaturated branched and cyclic non-polar hydrocarbons, and has meltingpoint of from 73 to 80° C. In certain embodiments, the wax comprises,alternatively is, a microcrystalline wax that is a solid at roomtemperature (25° C.). In some embodiments, the wax is selected to have amelting point within a desired application temperature range (i.e., thetemperature range within which the sealant is intended to beused/applied). It is thought that the wax, when molten, serves as aprocess aid, substantially easing the incorporation of filler in thecomposition during compounding, the compounding process itself, as wellas in during a de-airing step, if used. For example, in certainembodiments, the wax has a melt temperature below 100° C. and mayfacilitate mixing of parts (e.g. when the sealant is a multiple partcomposition) before application, even in a simple static mixer. In suchinstances, the wax may also facilitate application of the sealant attemperatures of from 80 to 110° C., alternatively 90 to 100° C., withgood rheology.

The amount of the rheological additive present in the sealant depends onvarious factors (e.g. the amount and/or type of the (I) copolymer, anintended use of the sealant, curing conditions to which the sealant isintended to be exposed, a presence/absence of a vehicle/solvent, etc.),and may be readily determined by one of skill in the art. In general,where present, the sealant comprises the rheological additive in anamount of from greater than 0 to 20, alternatively from 1 to 15,alternatively from 1 to 5, parts by weight, based on the combinedweights of all components in the sealant.

In certain embodiments, the sealant comprises a vehicle (e.g. a carriervehicle, such as a solvent and/or diluent). Depending on a selection ofvarious components of the sealant, the carrier vehicle may be, forexample, an oil (e.g. an organic oil and/or a silicone oil), a solvent,water, etc. As will be understood by one of skill in the art, theparticular vehicle utilized, if any, is selected to facilitate (e.g.increase) flow of the sealant or a portion thereof (e.g. one or moreparts of the sealant when the sealant is a multiple-part composition);as well as the introduction of certain components (e.g. the (I)copolymer, the chainextender, the end-blocker, etc.). As such, suitablevehicles are varied, and generally include those which help fluidize oneor more components of the sealant, but essentially do not react with anyof such components. Accordingly, the vehicle may be selected based on asolubility of one or more components of the sealant, volatility, orboth. In this sense, the solubility refers to the vehicle beingsufficient to dissolve and/or disperse the one or more components of thesealant, and the volatility refers to vapor pressure of the vehicle. Ifthe vehicle is too volatile (i.e., has a vapor pressure too high for theintended use), bubbles may form in the sealant at the applicationtemperature, which may lead to cracks and/or otherwise weaken ordetrimentally affect properties of the cured product formed from thesealant. However, if the vehicle is not volatile enough (i.e., has avapor pressure too low for the intended use) the vehicle may remain inthe cured product of the sealant and/or function as a plasticizertherein. Examples of suitable vehicles generally include siliconefluids, organic fluids, and combinations thereof.

In some embodiments, the vehicle of the sealant comprises, alternativelyis, a silicone fluid. The silicone fluid is typically a low viscosityand/or volatile siloxane. In some embodiments, the silicone fluid is alow viscosity organopolysiloxane, a volatile methyl siloxane, a volatileethyl siloxane, a volatile methyl ethyl siloxane, or the like, orcombinations thereof. Typically, the silicone fluid has a viscosity at25° C. in the range of 1 to 1,000 mm²/sec. In some embodiments, thesilicone fluid comprises a silicone having the general formula(R²⁸R²⁹SiO)_(|), where each R²⁸ and R²⁹ is independently selected from Hand substituted or unsubstituted hydrocarbyl groups, and subscript I isfrom 3 to 8. Specific examples of suitable silicone fluids includehexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane,decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane,octamethyltrisiloxane, decamethyltetrasiloxane,dodecamethylpentasiloxane, tetradecamethylhexasiloxane,hexadeamethylheptasiloxane,heptamethyl-3-{(trimethylsilyl)oxy)}trisiloxane, hexamethyl-3,3,bis{(trimethylsilyl)oxy)}trisiloxanepentamethyl{(trimethylsilyl)oxy}cyclotrisiloxane as well aspolydimethylsiloxanes, polyethylsiloxanes, polymethylethylsiloxanes,polymethylphenylsiloxanes, polydiphenylsiloxanes, caprylyl methicone,hexamethyldisiloxane, heptamethyloctyltrisiloxane, hexyltrimethicone,and the like, as well as derivatives, modifications, and combinationsthereof. Additional examples of suitable silicone fluids includepolyorganosiloxanes with suitable vapor pressures, such as from 5×10⁻⁷to 1.5×10⁻⁶ m²/s, include DOWSIL® 200 Fluids and DOWSIL® OS FLUIDS,which are commercially available from Dow Silicones Corporation ofMidland, Mich., U.S.A.

In certain embodiments, the vehicle of the sealant comprises,alternatively is, an organic fluid, which typically comprises an organicoil including a volatile and/or semi-volatile hydrocarbon, ester, and/orether. General examples of such organic fluids include volatilehydrocarbon oils, such as C₆-C₁₆ alkanes, C₈-C₁₆ isoalkanes (e.g.isodecane, isododecane, isohexadecane, etc.) C₈-C₁₆ branched esters(e.g. isohexyl neopentanoate, isodecyl neopentanoate, etc.), and thelike, as well as derivatives, modifications, and combinations thereof.Additional examples of suitable organic fluids include aromatichydrocarbons, aliphatic hydrocarbons, alcohols having more than 3 carbonatoms, aldehydes, ketones, amines, esters, ethers, glycols, glycolethers, alkyl halides, aromatic halides, and combinations thereof.Hydrocarbons include isododecane, isohexadecane, Isopar L (C₁₁-C₁₃),Isopar H (C₁₁-C₁₂), hydrogentated polydecene. Ethers and esters includeisodecyl neopentanoate, neopentylglycol heptanoate, glycol distearate,dicaprylyl carbonate, diethylhexyl carbonate, propylene glycol n-butylether, ethyl-3 ethoxypropionate, propylene glycol methyl ether acetate,tridecyl neopentanoate, propylene glycol methylether acetate (PGMEA),propylene glycol methylether (PGME), octyldodecyl neopentanoate,diisobutyl adipate, diisopropyl adipate, propylene glycoldicaprylate/dicaprate, octyl ether, octyl palmitate, and combinationsthereof.

In some embodiments, the vehicle comprises, alternatively is, an organicsolvent. Examples of the organic solvent include those comprising analcohol, such as methanol, ethanol, isopropanol, butanol, andn-propanol; a ketone, such as acetone, methylethyl ketone, and methylisobutyl ketone; an aromatic hydrocarbon, such as benzene, toluene, andxylene; an aliphatic hydrocarbon, such as heptane, hexane, and octane; aglycol ether, such as propylene glycol methyl ether, dipropylene glycolmethyl ether, propylene glycol n-butyl ether, propylene glycol n-propylether, and ethylene glycol n-butyl ether; a halogenated hydrocarbon,such as dichloromethane, 1,1,1-trichloroethane and methylene chloride;chloroform; dimethyl sulfoxide; dimethyl formamide, acetonitrile;tetrahydrofuran; white spirits; mineral spirits; naphtha;n-methylpyrrolidone; and the like, as well as derivatives,modifications, and combination thereof.

Other vehicles may also be utilized in the sealant. For example, in someembodiments, the vehicle comprises, alternatively is, an ionic liquid.Examples of ionic liquids include anion-cation combinations. Generally,the anion is selected from alkyl sulfate-based anions, tosylate anions,sulfonate-based anions, bis(trifluoromethanesulfonyl)imide anions,bis(fluorosulfonyl)imide anions, hexafluorophosphate anions,tetrafluoroborate anions, and the like, and the cation is selected fromimidazolium-based cations, pyrrolidinium-based cations, pyridinium-basedcations, lithium cation, and the like. However, combinations of multiplecations and anions may also be utilized. Specific examples of the ionicliquids typically include 1-butyl-1-methylpyrrolidiniumbis(trifluoromethanesulfonyl)imide, 1-methyl-1-propylpyrrolidiniumbis-(trifluoromethanesulfonyl)imide, 3-methyl-1-propylpyridiniumbis(trifluoromethanesulfonyl)imide, N-butyl-3-methylpyridiniumbis(trifluoromethanesulfonyl)imide, 1-methyl-1-propylpyridiniumbis(trifluoromethanesulfonyl)imide, diallyldimethylammoniumbis(trifluoromethanesulfonyl)imide, methyltrioctylammoniumbis(trifluoromethanesulfonyl)imide, 1-butyl-3-methylimidazoliumbis(trifluoromethanesulfonyl)imide, 1,2-dimethyl-3-propylimidazoliumbis(trifluoromethanesulfonyl)imide, 1-ethyl-3-methylimidazoliumbis(trifluoromethanesulfonyl)imide, 1-vinylimidazolium.bis(trifluoromethanesulfonyl)imide, 1-allyl imidazoliumbis(trifluoromethanesulfonyl)imide, 1-allyl-3-methylimidazoliumbis(trifluoromethanesulfonyl)imide, lithiumbis(trifluoromethanesulfonyl)imide, and the like, as well asderivatives, modifications, and combinations thereof.

The amount of the vehicle present in the sealant depends on variousfactors (e.g. the amount and/or type of the (I) copolymer, the manner bywhich the sealant was formulated, curing conditions to which the sealantis intended to be exposed, etc.), and may be readily determined by oneof skill in the art. In general, where present, the sealant comprisesthe vehicle in an amount of from 1 to 99, alternatively from 1 to 75,alternatively from 2 to 60, alternatively from 2 to 50 wt. %, based onthe total weight of the sealant.

In particular embodiments, the sealant comprises a tackifying agent.General examples of suitable tackifying agents typically include thosecomprising an aliphatic hydrocarbon resin (e.g. a hydrogenatedpolyolefin having 6 to 20 carbon atoms), a hydrogenated terpene resin, arosin ester, a hydrogenated rosin glycerol ester, or a combinationthereof. Specific examples of suitable tackifying agents include naturalor modified rosins such as gum rosin, wood rosin, tall-oil rosin,distilled rosin, hydrogenated rosin, dimerized rosin, and polymerizedrosin; glycerol and pentaerythritol esters of natural or modifiedrosins, such as glycerol esters of pale wood rosins, glycerol esters ofhydrogenated rosins, glycerol esters of polymerized rosins,pentaerythritol esters of hydrogenated rosins, and phenolic-modifiedpentaerythritol esters of rosin; copolymers and/or terpolymers ofnatural terpenes, such as styrene/terpene and/or alpha methylstyrene/terpene polymers; polyterpene resins having a softening point,as determined by ASTM method E28, of from 60 to 150° C., such as thoseproduced via the polymerization of terpene hydrocarbons (e.g. pinene) inthe presence of Friedel-Crafts catalysts, as well as the hydrogenationproducts thereof (e.g. hydrogenated polyterpenes); phenolic modifiedterpene resins and hydrogenated derivatives thereof, such as thoseproduced via acid-mediated condensation of a bicyclic terpene and aphenol; aliphatic petroleum hydrocarbon resins, such as those producedvia the polymerization of monomers consisting of primarily of olefinsand diolefins, those having a ring and ball softening point of from 60to 135° C., and also hydrogenated aliphatic petroleum hydrocarbonresins; alicyclic petroleum hydrocarbon resins and hydrogenatedderivatives thereof; aliphatic/aromatic or cycloaliphatic/aromaticcopolymers and hydrogenated derivatives thereof; and combinationsthereof. In some embodiments, the sealant comprises a solid tackifyingagent (i.e., a tackifying agent having a ring and ball softening pointabove 25° C.). Other examples of suitable tackifying agents includecommercially available varieties, such as the aliphatic hydrocarbonresins exemplified by ESCOREZ 1102, 1304, 1310, 1315, and 5600 fromExxon Chemical, and Eastotac H-100, H-115E, and H-130L from Eastman; thehydrogenated terpene resins exemplified by Arkon P 100 from ArakawaChemicals, and Wingtack 95 from Goodyear; the hydrogenated rosinglycerol esters exemplified by Staybelite Ester 10 and Foral fromHercules; the polyterpenes exemplified by Piccolyte A125 from Hercules;the aliphatic/aromatic and/or cycloaliphatic/aromatic resins exemplifiedby ECR 149B and ECR 179A from Exxon Chemical; and combinations thereof.The amount of the tackifying agent present in the sealant depends onvarious factors (e.g. the amount and/or type of the (I) copolymer, thetype and/or amount of other components of the sealant, an intended useof the sealant, etc.), and may be readily determined by one of skill inthe art. In general, where present, the sealant comprises the tackifyingagent in an amount of from 1 to 20 parts by weight, based on thecombined weights of all components in the sealant.

In certain embodiments, the sealant comprises a corrosion inhibitor.Examples of suitable corrosion inhibitors include benzotriazoles,mercaptabenzotriazoles, and the like, as well as combinations thereof.Specific examples of suitable corrosion inhibitors are known in the artand commercially available, such as CUVAN® 826 (e.g. a2,5-dimercapto-1,3,4-thiadiazole derivative) and CUVAN® 484 (analkylthiadiazole), which are available from R. T. Vanderbilt of Norwalk,Conn., U.S.A.

The amount of the corrosion inhibitor present in the sealant depends onvarious factors (e.g. the amount and/or type of the (I) copolymer, anintended use of the sealant, curing conditions to which the sealant isintended to be exposed, etc.), and may be readily determined by one ofskill in the art. In general, where present, the sealant comprises thecorrosion inhibitor in an amount of from 0.05 to 0.5 wt. % based ontotal weight of the sealant.

As introduced in various sections above, various components of thesealant may be utilized for multiple purposes, and thus certainadditives may overlap with regard to the components described herein.For example, certain alkoxysilanes may be useful as filler treatingagents, as adhesion promoters, and as crosslinkers. Additionally, thesealant may further comprise additional additives not described above,such as catalyst inhibitors, curing promotors, color-change additives,etc. Such additional additives are independently selected, and eachutilized in the sealant in an amount selected based on the indented usethereof, as readily determined by one of skill in the art. Typically,where present, the sealant comprises each of such additional additivesin an amount of from 0.001 to 10, alternatively from 0.01 to 5,alternatively from 0.1 to 1 wt. % based on total weight of the sealant.

As described above, the sealant may be prepared as a one-partcomposition, or as a multiple-part composition (e.g. comprising 2, 3, 4,or more parts). For example, in some embodiments, the sealant isprepared as the one-part composition, which may be prepared by combiningall components together by any convenient means, such as mixing. Such aone-part composition may be made by optionally combining (e.g.premixing) the (I) copolymer with various additives (e.g. the filler) toform an intermediate mixture, and subsequently combining (e.g. viamixing) the intermediate mixture with a pre-mix comprising the (II)condensation reaction catalyst and other various additives to form asealant mixture or the sealant. Other additives (e.g. the anti-agingadditive, the pigment, etc.) may be added to the sealant at any desiredstage, such as via combination with the intermediate mixture, thepre-mix, or the sealant mixture. As such, a final mixing step may beperformed (e.g. under substantially anhydrous conditions) to form thesealant, which is typically stored under substantially anhydrousconditions, for example in sealed containers, until ready for use.

In some embodiments, the sealant is prepared as the multiple-partcomposition (e.g. when the crosslinker is utilized). In suchembodiments, the (II) condensation reaction catalyst and the crosslinkerare typically stored in separate parts, which are combined shortlybefore use of the sealant. For example, the sealant may comprise a twopart curable composition prepared by combining the (I) copolymer and thecrosslinker to form a first (i.e., curing agent) part by any convenientmeans (e.g. mixing). A second (i.e., base) part may be prepared bycombining the (II) condensation reaction catalyst and (I) copolymer byany convenient means (e.g. mixing). The components may be combined atambient or elevated temperature and under ambient or anhydrousconditions, depending on various factors, e.g. whether a one part ormultiple part composition is selected. The base part and curing agentpart may then be combined by any convenient means, such as mixing,shortly before use. The base part and curing agent part may be combinedin a 1:1 ratio, or in a relative amount of base: curing agent rangingfrom 1:1 to 10:1.

The equipment used for mixing the components of the sealant is notspecifically restricted, and is typically selected depending on the typeand amount of each component selected for use in the sealant or a partthereof (collectively, the “sealant compositions”.) For example,agitated batch kettles may be used for relatively low viscosity sealantcompositions, such as compositions that would react to form gums orgels. Alternatively, continuous compounding equipment (e.g. extruders,such as twin screw extruders) may be used for more viscous sealantcompositions, as well as sealant compositions containing relatively highamounts of particulates. Exemplary methods that can be used to preparethe sealant compositions described herein include those disclosed in,for example, U.S. Patent Publication Nos. 2009/0291238 and 2008/0300358,which portions are herein incorporated by reference.

The sealant compositions made as described above may be stable whenstored in containers that reduce or prevent exposure of the sealantcompositions to moisture. However, the sealant compositions, may reactvia condensation reaction when exposed to atmospheric moisture.Additionally, when the water release agent is utilized, the sealantcompositions may react via condensation reaction without exposure toatmospheric moisture.

A cured product is also provided. The cured product is formed from thesealant. More specifically, the cured product is formed by curing thesealant, e.g. via the condensation reaction described above.

A composite article comprising the cured product is also provided. Morespecifically, the composite article comprises a substrate and the curedproduct disposed on the substrate. The composite article is formed bydisposing the sealant on the substrate, and curing the sealant to givethe cured product on the substrate, thereby preparing the compositearticle. The substrate is exemplified by, for example, an exteriorbuilding façade.

A method of sealing a space defined between two elements is alsodisclosed. This method comprises applying the sealant to the space, andcuring the sealant in the space, thereby sealing the space.

The terms “comprising” or “comprise” are used herein in their broadestsense to mean and encompass the notions of “including,” “include,”“consist(ing) essentially of,” and “consist(ing) of. The use of “forexample,” “e.g.,” “such as,” and “including” to list illustrativeexamples does not limit to only the listed examples. Thus, “for example”or “such as” means “for example, but not limited to” or “such as, butnot limited to” and encompasses other similar or equivalent examples.The term “about” as used herein serves to reasonably encompass ordescribe minor variations in numerical values measured by instrumentalanalysis or as a result of sample handling. Such minor variations may bein the order of ±0-25, ±0-10, ±0-5, or ±0-2.5, % of the numericalvalues. Further, The term “about” applies to both numerical values whenassociated with a range of values. Moreover, the term “about” may applyto numerical values even when not explicitly stated.

Generally, as used herein a hyphen “-” or dash “—” in a range of valuesis “to” or “through”; a “>” is “above” or “greater-than”; a “≥” is “atleast” or “greater-than or equal to”; a “<” is “below” or “less-than”;and a “≤” is “at most” or “less-than or equal to.” On an individualbasis, each of the aforementioned applications for patent, patents,and/or patent application publications, is expressly incorporated hereinby reference in its entirety in one or more non-limiting embodiments.

It is to be understood that the appended claims are not limited toexpress and particular compounds, compositions, or methods described inthe detailed description, which may vary between particular embodimentswhich fall within the scope of the appended claims. With respect to anyMarkush groups relied upon herein for describing particular features oraspects of various embodiments, different, special, and/or unexpectedresults may be obtained from each member of the respective Markush groupindependent from all other Markush members. Each member of a Markushgroup may be relied upon individually and or in combination and providesadequate support for specific embodiments within the scope of theappended claims.

Further, any ranges and subranges relied upon in describing variousembodiments of the present invention independently and collectively fallwithin the scope of the appended claims, and are understood to describeand contemplate all ranges including whole and/or fractional valuestherein, even if such values are not expressly written herein. One ofskill in the art readily recognizes that the enumerated ranges andsubranges sufficiently describe and enable various embodiments of thepresent invention, and such ranges and subranges may be furtherdelineated into relevant halves, thirds, quarters, fifths, and so on. Asjust one example, a range “of from 0.1 to 0.9” may be further delineatedinto a lower third, i.e., from 0.1 to 0.3, a middle third, i.e., from0.4 to 0.6, and an upper third, i.e., from 0.7 to 0.9, whichindividually and collectively are within the scope of the appendedclaims, and may be relied upon individually and/or collectively andprovide adequate support for specific embodiments within the scope ofthe appended claims. In addition, with respect to the language whichdefines or modifies a range, such as “at least,” “greater than,” “lessthan,” “no more than,” and the like, it is to be understood that suchlanguage includes subranges and/or an upper or lower limit. As anotherexample, a range of “at least 10” inherently includes a subrange of fromat least 10 to 35, a subrange of from at least 10 to 25, a subrange offrom 25 to 35, and so on, and each subrange may be relied uponindividually and/or collectively and provides adequate support forspecific embodiments within the scope of the appended claims. Finally,an individual number within a disclosed range may be relied upon andprovides adequate support for specific embodiments within the scope ofthe appended claims. For example, a range “of from 1 to 9” includesvarious individual integers, such as 3, as well as individual numbersincluding a decimal point (or fraction), such as 4.1, which may berelied upon and provide adequate support for specific embodiments withinthe scope of the appended claims.

The following examples are intended to illustrate the invention and arenot to be viewed in any way as limiting to the scope of the invention.

TABLE 1 Abbreviations Abbreviation Meaning 0-0719 Complex of Pt with1,3-diethenyl-1,1,3,3-tetramethyl- disiloxane Polyether Monoallylterminated hydroxyl PPO, 800 Mw Compound MM Hexamethyldisiloxane ETMTrimethoxysilylethyl tetramethyldisiloxane (ETM Linear refers to ETMwith >95% β-form, ETM refers to ETM with ~65% β-form, 35% α-form) T-9Stannous Octoate T-12 Dibutyltin Dilaureate IPDI Isophorone DiisocyanatePolyol 8000 Mw polyol FTIR Fourier Transform Infra-Red ATR AttenuatedTotal Reflection NMR Nuclear Magnetic Resonance mL Milliliters ° C.Degrees Celsius mg Milligrams Mn Number average molecular weightdetermined by NMR NMR Nuclear magnetic resonance N/A Not available (notmeasured)

Preparation Example 1: Synthetic Procedure for Preparing aSilicone-Polyether Copolymer

A dry 4 neck flask is placed into a temperature controlled heating blockand fitted with a mechanical stirrer, thermometer, dropping funnel, andreflux condenser. The flask is purged with N₂, and the polyethercompound is disposed therein. The flask is heated to and kept at 105° C.for 2 hours under vacuum with intermittent N₂ purging. The flask is thencooled to 85° C. 5 ppm of 0-0719 is added (as 1 wt. % solution of 0-0719dissolved in MM). The ETM is added drop-wise. An adiabatic exotherm isobserved with a 5-10° C. increase in temperature and the reactiontemperature is kept at 85° C. by adjusting the addition of the ETMaccordingly. The flask is heated to and held at 85° C. for five hours,and the reaction is deemed complete when the SiH concentration is below2.5 ppm (as measured via FTIR or ¹H NMR). The contents of the flask arethen cooled to room temperature and packaged to a Nalgene-containerunder N₂ flow. Table 2 below sets forth the relative amounts of thepolyether compound and the ETM utilized in Example 1.

TABLE 2 Materials for making the silicone-polyether copolymer Material:Polyether Compound ETM Quantity: 750.0 g (0.94 mol) 200.0 g (0.71 mol)

Example 1: Synthetic Procedure for Preparing the Isocyanate-FunctionalSilicone-Polyether Copolymer

A reactor is fitted with a mechanical stirrer, thermometer, droppingfunnel, and reflux condenser. The silicone-polyether copolymer preparedin Preparation Example 1 is charged to the reactor together with IPDI(with the amount of IPDI being such that the residual NCO after thecompletion of the reaction is target at ˜2.5-3.00 wt. %) and T-9catalyst to give a blend. The blend is stirred until a uniform mixtureis obtained. The uniform mixture is heated to 80° C. and the reaction ismonitored by % NCO titration. The uniform mixture is heated for 2 hours.The reaction is stopped when the target % NCO is reached. A reactionproduct including the isocyanate-functional silicone-polyether copolymeris then cooled to room temperature and stored under nitrogen. Table 3below sets forth the relative amounts of the silicone-polyethercopolymer, IPDI, and T-9 utilized in Example 1.

TABLE 3 Materials for making the isocyanate- functionalsilicone-polyether copolymer Material: Silicone-Polyether IPDI (residualNCO target: Copolymer ~2.5-3.0 wt. %) T-9 Quantity: 908 g 184.7 g 0.045g

Example 2: Synthetic Procedure for Preparing theSilicone-Polyether-Urethane Copolymer

A reactor is fitted with a mechanical stirrer, thermometer, droppingfunnel, and reflux condenser. The isocyanate-functionalsilicone-polyether copolymer made in Example 1 is charged to the reactortogether with the polyol and heated to 40° C. The T-9 catalyst is addedto give a mixture and the mixture is heated to and held at 70° C. forfive hours. The mixture is reacted for and monitored by ATR FTIR tocheck for the disappearance of NCO. The reaction is stopped after thecomplete disappearance of NCO. A reaction product including thesilicone-polyether-urethane copolymer is then cooled to room temperatureand stored under nitrogen. Table 4 below sets forth the relative amountsof the isocyanate-functional silicone-polyether copolymer, polyol, andT-9 utilized in Example 2.

TABLE 4 Materials for making the silicone-polyether-urethane copolymerMaterial: Isocyanate-functional silicone-polyether copolymer Polyol T-9Quantity: 205.6 g 542.0 g 0.0813 g

Preparation Example 2 and Examples 3-4

Preparation Examples 2 and Examples 3-4 are the same as PreparationExample 1 and Examples 1-2, respectively, with the only difference beingthat Preparation Example 2 and Examples 3-4 utilize Linear ETM ratherthan ETM.

Comparative Example 1—Comparative Silicone-Polyether-Urethane Copolymer

A comparative silicone-polyether-urethane copolymer is prepared byfollowing exactly the same procedures above in Preparation Example 1 andExamples 2-3, except that the ETM is replaced by an equal molar amountof methyldimethoxysilane.

Practical Example 1

30 g of the silicone-polyether-urethane copolymer of Example 2 is mixedwith 0.03 g of dibutyl tin dilaurate in a 40 g capacity polypropylenemixing cup for a Flacktek speedmixer, and mixed at 2000 rpm for 1 minuteto give a mixture. The mixture is cast onto a Teflon plate 10 cm by 10cm in size and with edge guard. The Teflon plate is placed in a roomwith relatively humidity controlled at 50%, and temperature controlledto be 23° C. The plate is left in the room to cure for 7 days, thenmoved into an air circulating oven set at 50° C. with atmosphericmoisture content not regulated, and kept in the oven for 4 days. Thesample is then taken out of the oven and cooled to room temperature.Dogbone specimens are cut from the sample with a carbon steel die fordetermining tensile strength, and small pieces are cut from the samplefor differential scanning calorimetry (DSC).

The dogbone sample size for the tensile test is 50 mm long with a narrowneck length of 20 mm. An MTS testing frame with a load cell of 100 Nfull capacity is used for the tensile test. The testing speed is 50.8cm/min. The strain is calculated as displacement over the length of thenarrow neck. Stress at break is calculated by dividing the peak stresswith the initial cross-sectional area of the narrow neck region.

Differential Scanning calorimetry (DSC) is conducted with a TAInstrument Discovery Series DSC2500. The sample is weighed into Tzeroaluminum pans (˜10 mg of sample) and analyzed on the instrument. Thetemperature is first ramped down to −180° C. at 10° C./min and then upto 200° C. at 10° C./min. The heat needed to keep up with the rampingprocess is recorded and the Tg is detected as an abrupt change in heatcapacity.

The physical properties measured in Practical Example 1 are set forthbelow in Table 5.

Practical Example 2

The same procedure is carried out as in Practical Example 1, with theonly difference being that 0.336 g of vinyltrimethoxysilane are alsoincluded along with the silicone-polyether-urethane copolymer of Example2 and dibutyl tin dilaurate. The physical properties measured inPractical Example 2 are set forth below in Table 5.

Practical Example 3

The same procedure is carried out as in Practical Example 1, with theonly difference being that the silicone-polyether-urethane copolymer ofExample 4 (with Linear ETM), rather than the silicone-polyether-urethanecopolymer of Example 2, is utilized. The physical properties measured inPractical Example 3 are set forth below in Table 5.

Practical Example 4

The same procedure is carried out as in Practical Example 3, with theonly difference being that 0.336 g of vinyltrimethoxysilane are alsoincluded along with the silicone-polyether-urethane copolymer of Example4 and dibutyl tin dilaurate. The physical properties measured inPractical Example 3 are set forth below in Table 5.

Comparative Practical Example 1

The same procedure is carried out as in Practical Example 2, with theonly difference being that the comparative silicone-polyether-urethanecopolymer of Comparative Example 1 is utilized rather than the inventivesilicone-polyether-urethane copolymer of Example 2. The physicalproperties measured in Comparative Practical Example 1 are set forthbelow in Table 5.

TABLE 5 Properties of cured silicone-polyether-urethane copolymer TgStress at Stress at Strain at Break from 25% Strain 100% Strain PeakStress DSC Sample (psi) (psi) (%) (psi) (° C.) P.E. 1 5.9 9.3 ± 0.9402.7 ± 33.9 37.6 ± 3.6  N/A P.E. 2 3.9 ± 0.3 8.1 ± 1.1 558.8 ± 9.3 49.8 ± 2.3  −63 P.E. 3 11.8 ± 3.4  32.0 ± 0.9  261.5 ± 57.1 74.0 ± 15.3−61.9 P.E. 4 13.7 ± 1.1  35.9 ± 0.6  291.0 ± 38.0 89.2 ± 12.7 −62.1C.P.E. 5.1 ± 0.4 8.5 ± 2.4 625.1 ± 86.9 72.5 ± 18.4 −62.5 1

Sealant Example 1

A pre-mix solution of aminoethylaminopropyltrimethoxysilane (as anadhesion promoter) and dibutyltindilaurate (as a catalyst) are combinedinto a one ounce glass vial. This solution is then mixed by hand until atransparent straw color is obtained, and the mixture is set aside foruse later in the formulation process.

A max 300 long mixing jar designed for use with the DAC 600.2 VACSpeedMixer is placed on a balance and tared. Thesilicone-polyether-urethane copolymer of Example 2, diisononyl phthalate(as a plasticizer), and vinyltrimethoxysilane (as a drying agent) aredisposed in the jar. The contents of the jar are mixed for 30 seconds at800 rpm. Precipitated calcium carbonate is added to the jar and the jaris placed into the mixer and mixed for 30 seconds at 1300 rpm. The jaris removed from the mixer and scraped by hand with a spatula toincorporate any remaining calcium carbonate on the walls of the jar, andplaced back into the mixer for another mixing cycle of 30 seconds at1500 rpm. The jar is placed on the balance and the ground calciumcarbonate is disposed therein. This jar is put back into the mixer for30 seconds at 1300 rpm, removed for hand scraping, and then mixed for anadditional 30 seconds at 2000 rpm. The mixture formed above is weighedinto the jar and mixed for 30 seconds at 1300 rpm and then hand scraped.A final step to de-air the material is performed. The solid mixing jarlid is replaced with one containing a hole to allow air to escape themixing jar when in the mixing/vacuum chamber. A program is run withcontinual mixing according to the following set points: 37 seconds ofmixing at 800 rpm to 3.5 psi vacuum pressure, 40 seconds of mixing at1200 rpm holding 3.5 psi of vacuum, and 35 seconds of mixing at 800 rpmto break vacuum to ambient conditions. The resultant sealant is packagedinto a six ounce SEMCO tube and set aside for testing at a later date.

Table 6 below sets forth the components and their relative amountsutilized in Sealant Example 1:

TABLE 6 Component % by weight Silicone-polyether-urethane copolymer32.89 Plasticizer 8.09 Precipitated Calcium Carbonate 39.47 GroundCalcium Carbonate 17.73 Drying Agent 1.22 Condensation Catalyst 0.1Adhesion Promoter 0.5

Sealant Example 2

Sealant Example 2 is the same as Sealant Example 1, with the onlydifference being that Sealant Example 2 utilizes thesilicone-polyether-urethane copolymer of Example 4, rather than that ofExample 2.

Sealant Example 3

Sealant Example 3 is the same as Sealant Example 1, with the onlydifference being that Sealant Example 3 utilizes diazabicycloundecene asa catalyst rather than dibutyltindilaurate.

Comparative Sealant Example 1

Comparative Sealant Example 1 is the same as Sealant Example 1, with theonly difference being that Sealant Example 2 utilizes the comparativesilicone-polyether-urethane copolymer of Comparative Example 1, ratherthan the inventive silicone-polyether-urethane copolymer of Example 2.

The physical and curing properties of Sealant Examples 1-3 andComparative Sealant Example 1 are measured. The testing methodologiesare the same when analyzing both Sealant Example 1 and ComparativeSealant 1.

Tack Free Time: A 100 mil thick slab of the particular sealant is drawndown on a piece of polyethylene terephthalate (PET). A small strip ofPET is then lightly pressed onto the surface of the particular sealantto check for cure. When no sealant is transferred to the strip of PET,the sealant is considered tack free.

Extrusion Rate: A SEMCO Nozzle Type 440 is affixed to a 6-oz SEMCO tube.A brief extrusion is performed to fill the extrusion nozzle. Three datapoints of three seconds time are each collected with an extrusion forceof 90 psi. The extrusion rate is then calculated in grams per minute asan average of the three data points.

The particular sealant is cured at 50% relative humidity and 23° C. forseven days. Durometer is measured by ASTM Method D2240, Type A. Tensile,Elongation, and Modulus are measured by ASTM Method D412. Table 7 belowsets forth the physical properties from Sealant Example 1 andComparative Sealant Example 1.

TABLE 7 Unit S.E. 1 S.E. 2 S.E. 3 C.S.E. 1 Extrusion Rate g/min 158 106104 128 Tack Free Time minutes >1 day 100 48 95 Durometer Shore A 39 3140 36 Tensile psi 220 145 184 159 Elongation % 494 268 265 227 25%Modulus psi 50 31 53 46 100% Modulus psi 117 94 136 118

The invention has been described in an illustrative manner, and it is tobe understood that the terminology which has been used is intended to bein the nature of words of description rather than of limitation.Obviously, many modifications and variations of the present inventionare possible in light of the above teachings. The invention may bepracticed otherwise than as specifically described.

What is claimed is:
 1. An isocyanate-functional silicone-polyethercopolymer having the following formula:

wherein each R¹ is an independently selected unsubstituted hydrocarbylgroup or halogenated hydrocarbyl group having from 1 to 18 carbon atoms;subscript a is 0 or 1; D is a divalent hydrocarbon group having from 2to 18 carbon atoms; Y′ is a polyether moiety; and X is an isocyanatemoiety having at least one isocyanate functional group.
 2. Theisocyanate-functional silicone-polyether copolymer of claim 1, whereinthe polyether moiety Y′ has the formula—(C_(n)H_(2n)O)_(w)C_(m)H_(2m), wherein each subscript n isindependently selected from 2 to 4 in each moiety indicated by subscriptw; subscript w is from 1 to 200; and subscript m is from 2 to
 4. 3. Theisocyanate-functional silicone-polyether copolymer of claim 1, wherein:(i) the polyether moiety Y′ has the formula—(C₂H₄O)_(x)(C₃H₆O)_(y)(C₄H₈O)_(z)C_(m)H_(2m), wherein subscript x isfrom 0 to 200; subscript y is from 1 to 200; subscript z is from 0 to200; subscript m is from 2 to 4; and wherein units indicated bysubscripts x, y and z may be in randomized or block form in thepolyether moiety Y′; (ii) the polyether moiety Y′ has a number averagemolecular weight of at least about 100; or (iii) both (i) and (ii). 4.The isocyanate-functional silicone-polyether copolymer of claim 1,wherein: (i) each R¹ is methyl; (ii) a is 0; (iii) D is C₂H₄; or (iv)any combination of (i) to (iii).
 5. A method of preparing anisocyanate-functional silicone-polyether copolymer, said methodcomprising: reacting a silicone-polyether copolymer and a polyisocyanateto give the isocyanate-functional silicone-polyether copolymer; whereinthe isocyanate-functional silicone-polyether copolymer is according toclaim
 1. 6. The method of claim 5, wherein the silicone-polyethercopolymer has the following formula:

wherein each R¹ is an independently selected unsubstituted hydrocarbylgroup or halogenated hydrocarbyl group having from 1 to 18 carbon atoms;subscript a is 0 or 1; D is a divalent hydrocarbon group having from 2to 18 carbon atoms; and Y is a polyether moiety terminating with an OHgroup.
 7. The method of claim 5, wherein the polyisocyanate: (i) has anominal functionality of at least 1.6; or (ii) comprises a diisocyanatecompound having the formula NCO-D′-OCN, wherein D′ is a divalent linkinggroup.
 8. An isocyanate-functional silicone-polyether copolymer preparedin accordance with the method of claim
 5. 9. A method of preparing asilicone-polyether-urethane copolymer, said method comprising: reactingan isocyanate-functional silicone-polyether copolymer and a couplingagent having an average of more than one isocyanate-reactive functionalgroup to give the silicone-polyether-urethane copolymer; wherein theisocyanate-functional silicone-polyether copolymer is according toclaim
 1. 10. The method of claim 9, wherein the coupling agent comprisesat least one of a diol, a triol, a tetraol, a pentaol, and a hexaol. 11.The method of claim 9, wherein the silicone-polyether-urethane copolymerhas the formulaX-D″-X, wherein D″ is a divalent linking group, and each X has thefollowing formula:

wherein each R¹ is an independently unsubstituted hydrocarbyl group orhalogenated hydrocarbyl group having from 1 to 18 carbon atoms;subscript a is 0 or 1; D is a divalent hydrocarbon group having from 2to 18 carbon atoms; and Y′ is a polyether moiety.
 12. Asilicone-polyether-urethane copolymer prepared in accordance with themethod of claim
 9. 13. A silicone-polyether-urethane copolymer having anaverage of more than one functional group of the following formula:

wherein each R¹ is an independently unsubstituted hydrocarbyl group orhalogenated hydrocarbyl group having from 1 to 18 carbon atoms;subscript a is 0 or 1; D is a divalent hydrocarbon group having from 2to 18 carbon atoms; and Y′ is a polyether moiety.
 14. A sealant,comprising: an isocyanate-functional silicone-polyether copolymer; and acondensation reaction catalyst; wherein the isocyanate-functionalsilicone-polyether copolymer is according to claim
 1. 15. A sealant,comprising: a silicone-polyether-urethane copolymer; and a condensationreaction catalyst; wherein the silicone-polyether-urethane copolymer isaccording to claim
 13. 16. The sealant of claim 14, further comprising afiller, a cross-linker, an extender, a plasticizer, and an adhesionpromotor.
 17. A cured product of the sealant of claim
 14. 18. Acomposite article comprising a substrate and the cured product of claim17 disposed on the substrate.
 19. A method of preparing a compositearticle, said method comprising: disposing a sealant on a substrate; andcuring the sealant to give a cured product on the substrate, therebyforming the composite article; wherein the sealant is according to claim14.
 20. A method of sealing a space defined between two elements, saidmethod comprising: applying a sealant to the space; and curing thesealant in the space, thereby sealing the space; wherein the sealant isaccording to claim 14.